Progress report. The bayan is still going extremely well, except for one setback. I felt sufficiently up to speed to take it along to the session at the Globe on the first Thursday of the month - and found, embarrassingly, that it's slightly sharp, enough for the sound to be gruesomely incompatible with all the English accordions and squeezeboxes there. As it's clearly very well in tune in the self-consistent sense, I can only assume this is some regional tuning issue. Accordion tuning is a major and not inexpensive undertaking at the best of times, and I gather there are special problems with bayans (see The Classical Bayan, by Henry Doktorski); so I think I'll have to live with this. It's not going to make any difference from a busking/solo point of view, or playing alongside tunable instruments.
I have to admit to an interesting sensation. I've dabbled with various instruments before. Generally, seeing virtuosos just makes me feel there are skill levels that are inhuman: I can't imagine how anyone can play like that. The odd thing is that with chromatic button accordion, I don't get that feeling. I admire the skill of virtuosos, and know I'll never be that good: but I don't feel they're on another planet. I think that must be a good sign; I've found an instrument that I'm very much in tune with.