I spent some quality time working on the headlight assembly this morning applying gratuitous amounts of liquid tape and replacing the the wires between the connectors from the back.
Liquid tape circus:
Replacement wires between connectors:
I used heat shrink tubing and the nylon mesh wire sleeving to keep the ends next to the connectors bundled and act as a strain relief of sorts to keep the flexing near the connectors to a minimum.
I carefully buttoned everything back up, reinstalled the headlight assembly, and...everything worked! Well, all the lights came on, and the Litronic lamps would tilt up when I switched the high beams on.
I'm not sure how long this fix will actually last, so I'm going to hedge my bets and look around for some donor harnesses in case I have occasion to go back in there to fix something.