I was watching Sea Hunt episode 12 season 4 and everyone was diving the blue can Voit 50 fathom regs. To my suprise one of the regs had black nylon clamps for the mouth piece. Also, same thing in episode 13. Thus this debunks the "They only had chrome Tinnerman's in 1960-61." statement. Ah Hah. This makes me feel better as finding chrome Tinnermans are a pain and I have black nylon on my sweety rebuild.
There seems to be a mix of chrome and black nylon on the four sets of blue can regs. Specifically you can see Mike Nelson with black nylon on the mouthpiece and the horns at approximately 19 minutes in to episode 12. Makes me feel good.