John,

My tolerances vary but can get vary hairy in a few spots. In a few spots it needs to be .01 of a mm and a few others .5mm is okay and will not effect play, fit, or finish. I prefer to keep it all tight though and right now going to be doing some experiemtnation with finishes to slow/stop shrinkage of the reed-pan/mechanism plate as that will add to the life span of the instrument (hey, they are already built to last about 100 years, minus the bellows, whats another one or two hundred to shoot for).

Bellows are the one weak point in modern concertinas. They will with time fail, but must well built ones will take 10 years minimum of hard daily play before doing so. With modern Phosphor bronze you can even make "brass" reeded ones that have a reed lifespan of at least 50 years soyou get the idea.

Once I get this contract closed am looking at setting up one CNC router to start making conertina reed shoes and talking to a few german firms I know to tongue them with either stainless steel reeds or with modern "brass" so that I can offer tradionally reeded instruments to the purist (It also allows me to make much smaller instruments, as I can than set the reeds in on a radial pattern instead of parallel).

Once the boards get here and bedded in with some test runs, I also am cutting some custom combs for a Suzuki that I own to make it more air tight and building my version of a slideless chromatic harmonica based off of Vern Smith's design, with some changes to decrease air loss in a few spots and mill some custom covers for it and also for the Hands Free Chromatic of Vern's that I own.

So you can see trying to keep busy as the body heals (just healing a good bit slower than I want myself too).

Michael