FYI my ring is a 70s vintage that many of us have picked up from GreatDealz.
Thanks, I've also seen the aluminum repros that Frets on the Net does. The difference between the '60s and '70s is the smaller outside radius on '70s and chrome vs nickel plating. Actually, I'm not sure about the plating on the '60s.
Aluminum machines and polishes fairly easily. With a template it should be possible to make rings on my inverted pin router with the tighter inside radius that matches EMG, Artec, Duncan, etc. and the outside '60s TBird shape.