yes I think that was about the time they stopped.
some say it was because the eletronic wirerings needed was too complicated as Topcon has that quite small opening (from Exata).. I don't know.
in the end they tried to make cheap cameras - they was unfortunately not good at all....

I agree that airforce would treat camera roughly. Never the less it is amazing how good they still work, and how high quality the lenses (still ) have..
Gotta love it