Rats! The one in the lower left is oriented the wrong way for 645 on 120 film...it looks like the old 6x4.5 on 127 size film...very interesting but unfortunately, its not at all useful to me. I am sure somebody else would be interested though.

What are the actual dimensions of the opening in the one in the lower right?

(ps: I don't have a digital camera either...I use the one in the iPad.)