Anyone familiar with the Yahama Piccolos?

I have a yamaha 81. It's a well used one I got a couple of years ago, I'm guessing it's from the '70s. The best thing about it is that it has no intonation issues. I play it with a tuner and it's pretty much spot on throughout the whole range. The G# key is a bit awkward for me, and it's hard to play some of the notes above high G. High E and F# is also a bit unstable. A bit of regulating may fix some of that. I tried a Hamig a few years ago and that would be my choice, but I'm happy with the yamaha.