"C", in this case, would indicate "C"onfederate. otherwise a Smith and a Confederate would both be stamped the same.
Hope this helps, Capt. Chris
_________________________
Capt.Chris Stanaback
RKCC/RKCA Founder
RKS #016
NRA Lifetime Member
CAPTSTANABACK@aol.com
WEBSITE: www.captstanaback.com