Find yourself a decent 1965 and use it's reverse as a guide.
After a while you will be able to spot the Type "C" pretty quickly
and accurately. Oh, and also look out for that elusive silver 65
Hi Harvey, long time no hear. I still have that 60 and 61. I may decide
to send them both along to you for a look. Still up in the air as to whether they are proofs or not. No dealers agree that they are proofs.