Here's one last post on this topic. This is a better picture of the actual camera, as modified by Red Williams, from the Smithsonian National Air and Space Museum:
"Ansco Autoset 35mm camera used by John Glenn on Friendship 7, the first U.S. manned orbital mission. Glenn used standard and ultraviolet-sensitive film in the camera which had been modified for left-handed operation.
NASA Photograph"
Here's a description from NASA:
Even the weight of a small camera mattered. Known for his camera expertise, Williams was asked to modify further the off-the-shelf Ansco Autoset camera Glenn would carry into orbit. He removed any parts unnecessary to its basic function, such as decorative leather or metal and replaced the larger hand-pistol grip with a smaller one.He did indulge in one luxury, adding a larger viewfinder taken off a Polaroid camera so Glenn would have a better view.
(Lots more info on the other camera modifications he did for NASA at that link above.)