Not sure if this is standard - or even recommended - practice, but many years ago my dad had the misfortune of cirlips coming out of all the pistons on his Indian 4, putting very deep tram rails in the cylinders - from memory some were up to 3mm deep! This he had fixed by getting the grooves filled with braze, or perhaps bronze weld, I can't remember and we wouldn't have known the difference back then in any case! The barrels are still in service, with no problems since the repair. Well no problems in the barrels in any case, the machine has had lots of other problems, but don't let me go there!
What do the engineers here think?