careful of the ears. I wear ear plugs when I play that thing.
Although there seems to be a real possibility to alter the fingering, I side with you, and would play it as it is.
I’m not one for complacency! 
First I plugged the C-nat. hole on the underside of the body.
Then I opened up the C-hole to 15/64”.
Finally I moved the F-hole 2 mm north of the edge of the existing hole and drilled it out to 7/16”. (Hindsight: I should’ve plugged the existing hole and moved well north.)
Now I have a Proper Irish Piccolo!
Jordan,
Until this thread, I’d never given any thought to modifying the little Yamaha flute (but for that matter, I’m not a flute maker, anyway), but this thread now has my interest, and I have a question, please. That is, have you made any discoveries about the sort of plastic the Yamaha is made of, and in particular, of what glue work best on it? Plugging holes on a plastic flute calls for glue, right?
TIA
Hey Cork,
I just used “Hot-Melt” glue to plug the hole. It is easily removed.
I belive the plastic is a form of PVC, sure drills and works like PVC pipe with more plasticizer in it.
I pondered what I could use to plug the F-hole if I were to relocate it. The problem is that a new F-hole will intersect the plug, so it needs to be workable. I would wonder about a J-B weld type product or some form of epoxy. I’ve got some white marine epoxy, but it doesn’t work well for drilling\milling (remains a bit pliable).
I think the modified Yamaha is a fine little piccolo! 
All the Best!
Jordan,
No, I have no grand scheme about going into the flute making business, none, but at such a low cost, it seems affordable even to make mistakes at whatever I could try with the Yamaha.
Again, thanks!
Hey Cork,
The Yamaha Fife is made of ABS plastic (looked it up).
Yeah, that seems about right. IIRC, it is somewhat softer than a polymer.
Well, that’s easy enough to deal with. A trip to the nearby plumbing store could get an appropriate glue by the bucketful.
Thanks, Jordan.
i agree: whiny babies. learn to play the concertina, and then let’s talk.
Oh the concertina… its terribly ridiculous and there are two different types aren’t there?
I’m afraid I want one… or two!
C-hole? do you mean the hole that R4 finger closes to get C?
It looks as if you also opened up the hole that R2 closes to get E.
Or did you merely confuse “C” and “E” holes when writing your post?
Hey Tweeto,
The tumb-hole on the underside of the piccolo body gets plugged.
Then the topmost tonehole gets opened up so sharpen C to C# and the hole that vents F gets drastically enlarged to make it F#.
Sillydill,
Ah, thanks for that distinction.
How does it sound? Does it now cross-finger C-natural the same as our main instrument, the simple-system flute?
Hey Tweeto,
The modified Yamaha is a nice playing little piccolo. C natural fingers OXX OOO, I also found that XOX XXXx works. Plus you still can play the bottom C XXX XXXx.
The F# is a bit overpowering, but would be improved if it were moved further up the body (towards the head), then the hole would be smaller.
All the Best!
Easy just tape up thumb hole together with either top or bottom hole (Try one at a time) to give you a standard 6 hole fife played with penny whistle fingering.
Lets know how you get on