Can I just use bolts rather than studs and nuts ?

 

Sounds like it came from a R50.

 

I hope not . That means the valves and cam are not meant to be used in an S . Is there a way to be sure?

 

From my experience, most cylinder head shops will remove any studs and such before they reman the head. That said the valves are different between the Cooper and the S however the cam is the same. Most inconel valves have a dimple in the valve face to distinguish them from standard stainless steel valves, that said "most" valves are like that, not all.