Actually, I don't think it is missing a fuse. There is a white box with 2 terminals which look suspiciously like the fuse terminals elsewhere in my cab. But in actuality, I think the terminals are just there for the wires coming from them. The fuse may be inside for all I know, or it may be unrelated. I think it will work fine.
Also, it turns out I DO have the video input cabling after all (hard to remember everything I yanked out 1 1/2 months ago.) 1 side is a 6-pin (with 4 wired) and a 3-ish pin with 2 wired, those go to the monitor I believe. Other side is 6 pins (Pac man PCB connector?) Question is how to wire these color and sync inputs based on the cabling, but hopefully I can find technical info on the WG 4600 series online...