A red-box on the electronic ignition might be a Boyer, although I'm not sure they made them for the SOHC4's. Does it say anything on the box? How about on the magnetic pickup plate where the points used to be?
Martek made ignitions for the 750, but I don't recall there being a control box and the pickups were optical (had one on a CB750F with a turbo I bought a while back). Basic DYNA ignitions also don't have a box, and if they do, they normally say DYNA all over them.
I did my own wiring from scratch on my XS650. Wasn't so bad.