Thanks for your reply Don. There are two colors of paint on the engine. A light blue and a dark blue. The dark blue is what’s visible in the photograph of the fuel pump. The engine model number is 5520, and according to information from marineengine.com, was made in 1960. Not sure how much difference that makes.
Try to post a picture of the entire engine showing the different colors, perhaps someone swapped the powerhead with the 1959 engine. Like others have said, a 1960 Fisherman would have a mounting port for a conventional OMC fuel pump on the starboard side of the powerhead.