I also have two f2.8 tessars both nickel one has a black front the other is all nickel. Would thes both be the same formula?

I did get a contax film cassette and two kiev film cassettes. Only the contax cassette works in the contax model I the kiev would have to be modified a hole would need to be drilled in the tab at the bottom of the cassette.

From what I understand a kiev shutter crate cannot fit in a contax and the shutter tapes are not the same size. Too bad someone can't come up with a better material for shutter tapes. Maybe a flexible piece of titanium?