Do not know what aircraft but it is a nice bit of equipment in excellent condition from the photos.
GSAP means gun sight aiming point so it probably goes with the AN-N6 GSAP camera. As far as I know that was the only one used at that time by the USN and USAAC/F.
Here are two articles from http://www.cameratopia.net/ covering the N6 and N6A cameras that I collected a couple of years back. Unfortunately the site appears to have died.