i send a mesage to wiseco to ask if there any chances to find fiting piston.
if not i'm redy to push out old sleevs and do the new ones and push back.
old pistons looks fine.no scoring.
in Poland i can do rings for this piston, but old rings have thin layer( maybe 0.10 mm) of chome or something in this kind.yamaha made in 1980's have 67mm pistons and ther is no problem to find std( 1 set is 25$) or oversize(
2 x piston kit is 62$)