I can tell you that I have two circular saws, both Black and Decker, and the base offset from the blade is different on them.
I made a homemade jig (2 actually - one is 8 feet long, the other is 5 feet long) to break down large panels: 1/2 inch birch ply with a 3/4 inch guide fence. I made the fence over size, then cut off the excess with a circ saw to cut to an exact dimension for that saw. I labeled the two jigs with the saw name and specific blade I used, so I'm sure to use the correct saw.
I don't have a picture to post, sorry.