Can anyone ID these old cabinets?

Morning all, Local junk shoppe owner asked me if I knew what these cabinets were, because he thought they might be computer-related, and although I have my doubts I said I'd ask here: http://www.patooie.com/temp/cabs.jpg The top one is about 18" wide and 18" deep, while the bottom one is more like 20" wide and 18" deep (all guesstimates with mk1 eyeball). The slots on both are about 2" high. Both have arms internally which are designed to slide the contents out partway when the doors are opened, and the arms on the green one are curved, suggesting that they held something cylindrical. Somehow they 'feel' too old to be computer-related to me - if I had to guess, I'd say they were maybe for canisters containing movie reels, but I suppose it's possible that they're far newer than I think and might be for some '60s or '70s disk packs / tapes / whatever... cheers Jules