Cunegonde has a two-headlight grille. 

After carefully inspecting the fuse rail, it appeared there was a decaying spade connector at #6. I crimped on a new one, now BOTH HI BEAMS WORK. I have 100% improvement :). But I want more. I want all four filaments to light. Suggestions, please?

Also, my PO-installed tach now works intermittently, instead of reliably. It appears to be powered from fuse #2, the parking light.

Neither lo beam works. 
There's no voltage in the yellow or yellow/black wires at the sockets.
Jumping the ground wires to the body makes no difference.
There's >13.2V at the black/yellow wires X behind the instrument cluster rocker switch
There's <4V between the black/yellow X and white/black 56 with low beam, >13.1V with hi beam switch on
Nothing at fuses #3 or #4. 

Both headlight grounds behind the dash have good continuity. I'll upgrade the ground (and supply) wires to 12g when I upgrade the lighting with relays and sockets for brighter bulbs than the current Hella 100/55W in Bosch motorcycle reflectors. 

Thanks volks.