gg: Maybe a single drop of Loctite screw-lock will ensure it doesn't move on the shaft anyway?
Personally, I would remove and silver solder the flywheel, IF it needs to be repaired. Then carefully ream the hole back to size. (The Cast Iron may shrink very slightly with heating, or it may not be significant to affect the sliding clearance onto the shaft? (N.B. Cast iron exhaust manifolds can shrink 1 to 3% in their lifetime - but after many heating cycles... - Maybe the carbon is burnt-out by heating? Can a material scientist explain please? A curious material! - I once bronze brazed the skirt on an engine cylinder with a short (1") crack in it. Afterwards the skirt was thou or 3 smaller than the rest of the bore. - The piston was a good fit in the top 3/4 (above the base flange of the cylinder), but tight for the last 1/2" or so, A judicious application of emery where the engineer's blue indicated made a good fit, but a house moved forced the sale before I got that bike built and running, so I don't know if the repair worked...).
K2