I went through this not long ago. First step...take the cylinders and pistons to a good machine shop and pay them to take good measurements. Max clearance is 0.120mm, which is basically huge--4.7 thousandths. If you're at 3 thou or less, flex hone them, buy next size up rings and trim ends to fit.
Oversize pistons are only for reboring to next size up.
Unless it's a race motor, button it up and run it.
1974 R90/6 motor w/1050 kit; twin plugged; installed in...1970 R60/5 frame; RM125 front end; KZ1000 Police Tank.