Old Perkins 4.107 Engine Number Follow-up

Reggie, I just receved an email from another source (A Westerbeke dealer rep in Pensacola) and he states: The "C" at the end of the serial number designates Chrome Liner outside diameter for marine use. It is in all probability a 1964 engine according to the serial number. I think this nails it for me. 2 out of three sources say chrome liners. I'll buy that. Mike