hi guys, thanks for letting me join your group

[BA80]

oh, one more thing, i tested the petcock:
in On/Reserve position: the rear-facing outlet will spill fuel (no vacuum needed)
in Prime: the front-facing one will spill.

That's because it has a special tank on it. No vacuum to the petcocks. The special had the vacuum operated fuel cut off valve mounted to the top of the carbs referred to as the "octy".

[DGXSER]

Yes to replacing the fuse box. Those old glass type fuses and the holders go bad. All looks good, but the holder is not tight on the fuse and gives poor conduction, or they will snap off.

On the Special model, which your tank is off of, the fuel petcocks themselves will flow with no vacuum. On those models there is a vacuum operated fuel valve (OCTY). The ON/RESERVE outlet of the petcocks runs to the OCTY and when it gets vacuum from the engine, it opens to let fuel flow to the carbs. The PRIME oulet is connected with a T to the fuel line running from the OCTY to the carbs, bypassing the vacuum valve. With no vacuum valve or OCTY you can simply run the fuel line from the ON/RESERVE to the carbs, preferably through an inline fuel filter.

[bikerphil]

is there supposed to be a black plastic turning knob above the fork?

The black rubber piece over the fork cap (78-79 Standard forks only) is just a cover to keep the crap/water out, the spring preload adjustment is done with a large flat head screwdriver.