Damn, ended up with another novella here.
Can't guess the brand of that.
Timing is done with a strobe. The marks can be seen through the hole. If the engine runs, no problem doing timing.
Unless you moved the plate it should be set OK or close. Doing regular timing adjustment compensates for points wear, no points = no wear. I have a Martek ignition that has not needed timing adjustment in 30 years or so. Sometimes I fiddle with total advance (finding the fine line between max horsepower and preignition) but it does not vary after being set.
This one seems similar to Dyna or Martek (and others) in that there isn't a way to adjust 1-4 vs 2-3, only the full plate can be moved.
I see separate 3 conductor wires to each pickup meaning almost certainly there is a remote circuit box somewhere. Integrated units usually only have 3 wires: to +12V power in, coil 1-4, and coil 2-3 (maybe a ground wire also but they can ground to the engine case). It is possible that it's stand alone, with one of the three wires in each module going to a coil but I have never seen one like that. It may be a home brew system McGuyvered up from two single cylinder motor ignitions... but it appears factory made rather than a home shop one-off and the individual modules do not look like any motorcycle OEM trigger units I've ever seen.
Assuming it's a points replacement EI for standard Kettering ignition, the blue and yellow coloured wires at the actual coils (assuming stock wire colours) can be used for static timing. A test lamp from one to ground will go on and off as the crank turns: the exact point in crank rotation (forward) when the lamp goes on is the ignition point: set the timing plate so that happens at the F mark. The engine should run, timing is not so critical at low RPM. Then use a strobe for final adjustment.
*** DO NOT RUN ENGINE WITH THE ALTERNATOR SIDE COVER OFF! Major oil gush and probably lost gallery plug will result ***
Best is to set timing to the advance timing mark at higher RPM (3K+) and basically ignoring the idle timing F mark.
Possibly this is a more complicated CDI ignition - static timing isn't as simple on those. Normally they use special coils though so check if yours are originals.
Very important: do not turn the crankshaft with that oh so tempting large nut on the advancer shaft (middle of pic). It is actually turning a small weak bolt (6mm I think), easily snapped off, and a PITA to fix. Use the alternator rotor bolt on the opposite side, removing the alternator cover will let you grab the rotor by hand or strap wrench should the bolt just thread out.
(you can use the big nut if super careful and gentle for a bit of rotation, but have the plugs out and don't go backwards much at all as that engages the starter clutch and you absolutely won't be able to turn the crank and starter motor from there - the bolt will snap)
