"PS it would be extremely inforative to spin Lister-oid flywheels to distruction. Different brands, foundrys, alloys etc."
what would be the purpose,, i doubt the indian metallurgy is exact enough to get any useful data.
if you tested 10 from a supplier and they all passed the next 10 might be better or worse,,
staying within the engines rpm parameters, i am unaware of any failures,, have you heard of one failing at the design rpm?
bob g