V

Pulled out the old multimeter and tested the 18/19 connection and the red LED connection for continuity.

The ground wire from the red LED to the yellow LED was no longer attached at the yellow LED, meaning the red LED was not grounded.  So I soldered it back... the wire is a little too short, so this might happen again... these ground wires were pretty much the first connections I soldered, so it is no surprise that I screwed one of them up.

No problems with the path from the shift register to the ribbon connector for the 18/19 wedges, so I just heated up the joint and added an itty bit of solder.

Plugged the sucker back in and both the light and the 18/19 wedges worked.  Ran through a successful test of all wedges (just the single, not bull or double/triple, so i could be in for an unpleasant surprise later).

Everything appears to be working correctly, so I will just connect the speaker wires and screw the perfboard into place.  Methinks I will re-drill a few of the mounting holes since I had to bend the board a little to fit on the mounting posts and I cannot imagine bending it is helpful to the quality soldering job.

Another worry is the ribbon connector looks to be connected a little too close to the dart board, cause it is sort of looping up and may create a situation with the ribbon, the near-edge of the contact sheets and/or the cover -- in other words, there is a little too much slack in the ribbon so it protrudes up too high and to flatten it out results in the contact sheet lifting up from the plastic wedges a little.  We'll just have to wait and see what happens here, it may just work itself out and be happy,

Anyway, the gist is, yeah, victory, yay team.  I know it works and if it doesn't stand up to the abuse for which it is destined, I only have to repair and tweak.