It was a Feadan D I bought sometime around 1982 in Newport, Rhode Island at an Irish shop. I fooled around for a few weeks and then put it up. In 2002 I had a heart attack which required a bypass operation. I was told to do something to build up lung power. So I took out my old trusty Feadan and began to learn. The original Feadan I bought is still a very good whistle. BTW that is not a mispelling It was a Feadan not a Feadog although I love my Feadogs as well. Feadog was probably my second whistle.
My first whistle was a Dixon high D with brass body. I played it a bit but couldn’t get on with it. The second one was a Rose blackwood whistle. I never touched the Dixon again.
a walton in D, bought in 1980 ish. I learned a few tunes but was banned from the house and put it away.
4 years ago I started playing again with more success, but not with that Walton. It is without a doubt the most horrendous whistle I have ever heard. No wonder I gave up.
First whistle played was a Feadog given to my mother Christmas 2000, but my niece took that one over. First whistle owned was not one but three – a tweeked Clark Original D, a Walton’s Mellow D, and a Feadog (I think), ordered from The Whistle Shop on March 17, 2001.
Clarke Sweetone in D and Claire C. Both bought at the same time. The Clarke for £4.50 and the Claire £5.40.
Not played nearly enough.
Mine’s a brass/red cap Gen. C, -68 and i still have mine! 
Walton’s Little Black. I ordered three of them at once because they were less than $4 each. I goofed one up trying to tweak it, then managed to fix it somehow. That original purchase began my decline into WhOA. Now I have 21 whistles, with no relief in sight
That was my guess too, since it only seems to have started since I took the head off. Will I still be able to move the head around to tune it with the teflon tape, though? (that’s why I wondered about the silicone grease-- might seal off any gaps, but also might make it easier to get that head to slide.)
Should still be able to move it around if you don’t use too much.
And the stuff is really cheap, if it doesn’t work you won’t be out too much.
My fourth whistle is a Generation Bb. My third was going to be a Gen C, but the shop had restocked. They had a whole fleet of Generations, Megs in C and D, and Clarke Originals in C and D, so I wound up with a Clarke C and this one.
The evidence from all these whistles says that my first, a Gen D, really was a dud. Where the others, with more wind, flip neatly up the octave, the dud D has a vast area that sounds like tree-frogs at war.
So my fifth whistle will be another Gen D that works. What the Gens have (both the Bb and the D when it’s not going (somebody changed my word – let’s go with “totally”) insane) is a beautiful rich tone with a lot of higher harmonic. Very distinctive. In terms my old organist buddies might use, the Clarkes are flutes, and the Gens are diapasons. Can’t do without that.
My fist whistle was a Green top Feadog D that I purchased some 20 odd years ago. Up until this Christmas I have not played tin whistle much as I like playing the boehm flute.
I came accross it in an old drawer a couple of months ago and my interest in tin whistling has been re ignited. My wife bought me a Sweetone recently which with a bit of bluetack to quieten it makes a great practice whistle for when the family is in the house
Andy
My first, bought as a present for me at least ten years ago was a feadog D, it came with a book. Between it and my generation C it is my favourite.
My first was a Hohner C (yes, the famous), bought about 35 years ago and I still have it ! 
My first whistle was a Generation Red top D around 1973 and it was quickly joined by several others red and blue in bB C D bE F and G and then by a Clarke in C with the wooden block. I played them now and then but preferred recorders as had trouble with octave D fingering as it is the bE fingering on a recorder. Tried the Clarke C and D with plastic top but still my playing was not as fired up as when playing recorder.
Bought a Howard low D and Susato Low G last year and discovered the delights of quality whistles so have bought a clutch of whistles including Kerry, Susato, Syn, Howard and Ferris since. Love playing now and recorders have taken a back seat. Coping with high D and other fingering changes and adapting F recorder technique to the G whistle as pitch is the same.
I think playing those early whistles and struggling with the very average quality sound they produce has made me appreciate the lovely whistles I can get now more. It’s a shame I waited so long.
Eamon from OZ
My first whistle was a Clarke Original in C - I still have it and like it quite a bit (but my best Clarke Original is an unpainted D). I didn’t know anything about tin whistles when I bought it (that’s the main reason why I chose a C whistle - I didn’t know it would come in handy later on), I just wanted to try this instrument that looked so totally simple. It has been fun and a serious education ever since to get to know the whistle and the culture behind it… After some serious bouts of WhOA, I’m now keeping a well stocked whistle roll (with a choice of whistles from high F to low Bb) around; I’ve even built some of my own, following Guido Gonzato’s great manual.
M.