Here are the pic of cam shaft from Peugeot 504 i send to Ron Chernich in November 2003 ( http://www.modelenginenews.org/ed.2003.11.html#tt2 )

The cast iron between the camlopes was easy to turn at lathe except the camlope was very hard and impossible to reverse back to unhardened cast iron.


RAMJET..
To be honest: Are you really afraid for the piston ring or ring gap will be wrong or too big while your engine worked very well with the original piston ring [sm=confused.gif][sm=confused.gif][sm=confused.gif][sm=confused.gif]
I found the thread is so long it is only talk about the tema was about "ring end gap" and there was mostly about piston ring mateiale that you may blends between model enginen and auto-/motorcycle engine.