Black grip question

[Dave Sanders]

I don't want to beat a dead horse, but wondered about these grips. They came from a BYF 42 4257 g and bought from a major dealer that is one of the major dealers on this website, so I really didn't question the grips and bought it from him in the early 90's. As of late, more info has come about and I wondered about the authenticity of these.I found some information and pictures on Stills website, but can't say on these. I did the hot pin test, and the material is bakelite according to those tests, but it really doesn't match up to any of the examples I have seen. Any opinions?
Dave