This is a Gun Sight Aiming Point Camera. G.S.A.P. 16mm film, Bell&Howell. standard 16mm 50' cartridge compatable also with Filmo cartridge cameras.
I have this camera currently, which is a naval camera. Still trying to find out which aircraft this would have been used on. F8F?
Also there is an image erection device which I don't have.
I will have to find out how to trip the shutter w/o the power, as I assume that might be the way the boresight was used on the airframe. ]
See here for a titling device. This allows the pilot to put a labeled leader on the film
Bell and Howell Titler
This camera came with a Kodak Kodachrome loaded cartridge, which of course is probably a brick as noone has any chemistry for Kodachrome, and certainly it would be horribly expensive to get 50' developed due to the amount of chemistry required for movie film.
Luckly there is no lost color footage from WW2, most likely because the capacity indicator is at 50' showing no usage.