Denniss, I think you may be thinking of the shrage muzik setups.
Just about all Ju-88Cs that entered production had 1x MG/FF. There was a later model that started with the MG151/20, but this never entered full production. There also is a ventral setup that added 2x more 20mm cannons, but I've only ever seen proof of this existing on the later Ju-88G night fighter models. The gondola you see on the Ju-88Cs doesn't have the same shape and either has the glass for the camera setup (very common) or is faired over and smooth -- no guns installed.
The only examples I see that add 1 or 2 more MG/FF are those behind the trailing edge of the wings and firing upwards. Some of those even played with MG151/20s in the same location. That would be one of the bomb bays repurposed for night fighter use. The daytime maritime patrol loadout would typically have some bombs in there to better attack light surface ships that threatened the U-boat fleets.
Against things like Sunderlands and Catalinas, that single MG/FF was adequate for (1940 standards).
