The sounding length (with a short ruler, sorry, not a tailors measure tape) = 575mm.
V
Oho! If that’s within a few mm, you’re probably in luck - the flute should (no guarantees!) play acceptably at modern pitch, probably with the tuning slide open about 1/3 to 1/2 its length, depending on player’s embouchure style. Worth restoring.
Great to hear! I’ve measured it 3 times now and its consistently within 575mm (ie, 574-575-576mm).
I plan on repadding it myself (I’ve done plenty of sax and clarinets before) and taking into a tech for the crack and the cork stopper.
Then I just need to learn how to play it (!!!) 
V
Lovely photos dubrosa22. Appears you have a ‘find’!
I see it has ‘needle’ springs, which speaks to a fairly recent, relatively speaking, build date.
If the hardware is maillechort I would avoid Brassotm as it leaves residue. I would search out 4000 grit went/dry paper. Rockler International supplies it. It goes under the generic name ‘Tri-mesh’.
Bon marché!
Bob
I’ve also measured from the middle of the C# hole to the middle of the Eb key (as prescribed in McGee’s excellent website http://www.mcgee-flutes.com/CsharpEb.htm ) and it comes to = 255mm.
Does that put this flute in the A430Hz range potentially? 
FWIW, I have a flute that shares many build characteristics with your flute. I measure the C# to Eb distance at 250 mm, possibly 251. I do not have the keys off to measure. I am not an especially ‘flat’ blower, but with the flute well warmed up and with a slide extension of 8 mm I get an A=440 tone. My bottom ‘D’ reads out at 291 Hz, or about one cent low.
I am not entirely certain how predictive Terry’s survey of measures is in this case. Perhaps you could ring him up?
Bob
I have to say that I don’t find Terry’s “indicator” to work as he hoped it might. Despite the limitations to using sounding lengths which he correctly described, SLs still work quite usefully, whereas the C#-Eb length does not, at least as an indicator of probable actual playing pitch of a flute. It may say something useful about scaling and thence probable intonation issues, but it won’t give you the playing pitch.
That said, it is more common for French flutes to be made for diapason normal A=435. But DN flutes usually have SLs c600-610mm and the ones I’ve measured have C#-Eb lengths c260mm. A modern pitch French flute I have has a SL of 580 and a C#-Eb of 248mm.
As for Brasso, it doesn’t leave a residue if you buff with a dremel (or bench buffing wheels) or use metal wadding or rinse with Meths or whatever after using it. I do tend to prefer the wadding except for the most stubborn deposits.
I’ve practised awhile (it’s a bit hard on a pad-leaking flute!) but I can play all the notes in the first octave on the top section pretty well.
So I got out my digital tuner and C#, B, Bb, A, G# and G all play in tune A440. I was stunned when it light up green for every note! (My main instrument alto sax rarely does that straight off!) This is with the tuning slide out 13mm or so, btw, which was a lucky ‘ear’ guess. Plus I gather with more playing it would need adjusting due to warming up (or cooling down).
Does this mean I can call it a A440 flute or do I need to measure more notes and into the second octave to draw that conclusion?
Many thanks for all your help!
V
No, I think you’ve proven the pudding adequately. Yes, you can call it “usable at 440”.
Once fettled up and as your embouchure improves, it may well play at 440 with the slide somewhat less open (also depending on atmpospherics), but if you’re getting the results you relate as-is, and given the SL prediction, I think you’re in business. It will probably have a slightly flat foot end, but hey… It might not.
Wonderful! Time to repad and get practising! 
I have made an identification breakthrough!
Thibouville-Buffet A. Paris
I found the same flute in an old for sale listing with 3 photos that show the very flute as mine (the key orientation on the C-foot being the most recognisable and unique feature). The first image is the flute that was sold by Mickie Zekley many years ago now and the second image is my flute’s c-foot (prior to oiling and cleaning!):
For sale listing located here: http://www.larkcamp.com/oneofakind.htmlx#French%20Flutes
Of course my flute has a repaired barrel and the crown and stopper appear to be slightly different but otherwise I am certain it is the same maker/model.
As said previously I can find no stamp or markings on my flute whatsoever. I do know that the Buffet clarinets (R13, etc.) are renowned for having stamps on them that practically fall off if you look at them too long). The head-joint and second joint each have only 2-3mm by 0.5mm ‘nicks’ where the stamps would be, nothing more. Suggestive…
I think there’s more going on. Either this is a Thibouville-Buffet stencil (unlikely and rather pointless, why wouldn’t you stamp it with another name?) or the finish and stamps on my flute have been over-zealously restored and the stamps sanded off. There is a heavy stain/varnish on my flute that seems after-market and a tad heavy handed in some places. Anyway just a thought, I have no idea how commonplace that would be, or if it is ever done?
I can now play down to D quite well, but all of the keypads on the lower joints are no good except Eb
V
Bravo!
Of course it could be the exact flute. . .or not. Mickey has been buying and selling flutes for a long time, as did his father. . .and it could have been ‘restored’ by one of his minions. And of course the late, celebrated, Paul Davies isn’t here to be interrogated!
Bob
Highly unlikely I’d say. I found it in an auction house in South Australia, in not exactly the kind of condition I’d expect if had been purchased recently from a restorer at top price. Plus mine doesn’t have the stamps that are visible on the Zekley flute.
I did query Mickie about said flute, but I only received a prompt but curt ‘SOLD’ in reply.
I’ll have to read up on him, sorry.
The characters past and present in the flute game put the saxophone folk to shame! 
V
I’ve been meaning to post this for a while and not getting around to it. You didn’t look at the right page on oldflutes.com, Bob!
Indeed, those 1832 Boehm C-foot joints do look remarkably like my C-foot.
Since they are conical I suppose they are essentially (acoustically?) identical.
Last night I manged to blow down to C# and C and then up an octave D, E , F#.
Still needs to be repadded and some corks here and there.
V
The general mechanical idea of that foot-joint arrangement wasn’t original to Böhm, mind you. But I reckon that’s the inspiration for similar feet on later French flutes of whatever system (with more elegant French metalwork), prior to the adoption of the modern rod-axle design.
I once again disassembled and oiled the wood and bore and also polished the keys once more a bit more thoroughly in preparation for re-padding (with silicone until leather pads arrive from the US) and I found a curious hallmark on at least 4 out of 8 keys:
Not sure what this symbol is called, it’s familiar but not so that I can name it. After some inconclusive Googling I found something like it: triskelion. Or maybe not.
As I’ve mentioned earlier there are 'O’s stamped on each key, an ‘E’ on one key and a ‘7’ on another.
And a few have hand scored roman numerals “VI” which Terry McGee has made an attempt at chronicling here:
http://www.mcgee-flutes.com/Keymarks.htm
Also there is a discrete ‘E’ and ‘4’ stamped between the busy cluster of posts on the foot joint. Too small and dark to photograph well.
After the silicone set and the excess was mostly successfully removed I can now play into the second octave. I bungled the short F and Bb silicone pads though, not closing smoothly. Can’t wait to re-pad properly with shellac and leather pads!
So far my repertoire has been scales and some transposed Jewish melodies I play on clarinet; I really need to start playing in earnest.
V
Somewhere in one of Anthony Baines’ books I ran across a mention of the French woodwindmakers having a network of craftsmen that they farmed out their keywork to, to be made on a piecework basis. This might provide a clue about the stampings on your keys. Not ‘Hall Marks’ as such, since the metal is base, but as identifiers of various contractors’ work.
Bob
Thanks Bob, it makes sense that there were common key forgers for multiple flute makers.
I’m reading lots online and plan on getting a few books. Music and history:
Early Flute by Rachel Brown
The Flute by Ardal Powell
The Essential Guide to Irish Flute and Tin Whistle - Grey Larsen
A Complete Guide to Learning the Irish Flute (aka ‘Timber’) - Fintan Vallely
As you can tell I get into the history of instruments and want to know all I can about their makers. I find it all quite fascinating!
Today I finally finished oiling, polishing, padding and corking!
Getting on with playing. Low D and below is the biggest struggle, I’m assuming that’s normal? I know that on tenor saxophone Low D and below can take weeks or months to play with any sort of consistency. Strangely Eb is dead easy.
V
Ah, you haven’t removed the metal cladding on the barrel. That’s a crack repair, right? It rather spoils the flute’s looks, even all buffed up! Forgive the question, but you have checked everything there is sealing? And the stopper? Suck tests? The slightest leak up there would be quite enough to kill your bottom end regardless of embouchure development. Even for a complete beginner, yes, those low notes are the most difficult, but they shouldn’t be completely unobtainable. Getting the foot key regulation spot on may be tricky, and open standing padded keys with leather pads can also be problematic even if the action is perfect because the pads don’t get a good , permanent hole-rim impression in the same way as closed-standing keys. I always find I have to keep micro-adjusting and fiddling with the set-up of flutes I have restored for a good bit of play-testing before I have them just so…
Books-wise, to add to your shopping list, you should read Böhm’s own Treatise (available online here: https://archive.org/details/flutefluteplayi00bh) because of the understanding it offers. Fitzgibbon is worth a read too, also available online (https://archive.org/details/storyofflute1914fitz). Philip Bate (https://books.google.co.uk/books?id=qMTCQgAACAAJ) and John Solum (http://books.google.co.uk/books?id=6N8sAAAAMAAJ) also produced useful flute history works. Last but most assuredly not least, get hold of Rockstro’s Treatise (http://books.google.co.uk/books?id=VsAIAQAAMAAJ). It isn’t in print nor, SFAIK, as yet available as a scan online, but you can pick up second hand copies. It’s invaluable (and not cheap!).
If you want to know about the makers, none of the above will tell you all that much - just who was to blame for what innovation… But there is a book (I haven’t read it) about some of the great French flute-makers by Tula Giannini (https://books.google.co.uk/books?id=O74IAQAAMAAJ).
Of course, there’s loads of brilliant stuff on Rick Wilson’s and Terry McGee’s websites, both of which you should read in their entirety!
If you’re buying Irish flute tutor books, add Conal O’Grada’s to your list. I haven’t seen the new edition of Fintan Vallely’s book, but the old one had some stuff in it (mostly flute history stuff rather than playing instruction) which was tosh. Useful and amusing book, but take with pinch of salt. Grey Larsen’s book is always controversial. I’m sure it’s useful, but if you search this forum you’ll find lots of varied opinions about it.