I sold the remaining same sets I had,including JMattisons personal frame.These were originally handed out by Chevrolet to key personal back in 1966-67 at first,as a token of their appreciation.
Read Here.....My pics are deleted,but were the same as in your picture & had "CHEVROLET-BAYCITY" cast on the backside.
There were recently being repopped,but those don't have "Chevrolet-BayCity" cast on the backside.