So far I only knew the all-black version from one single photograph in a handbook on the AE-1 from the 70s (I got quite a lot of Canon FD books).
The caption of that photo states the black version being offered on request.
Thus it seems to be a rare version.
Can you elaborate on that? Was it available throughout the production time?
(In one Canon publication there is a black AE-1 Program, but I have not come it across either.)
Today I got my own black sample. The base cap is definitely from brass. (We once had some discussion whether the base cap of the AE-1s is from brass or plastic. I got plastic ones too.)
The top cap is from coppered plastic. One may wonder why it is coppered, but I assume for electrical-field shielding.