After adding the ability to sense ambient light so it can calm itself when the light is dim I finally realized that the clock's timing was drifting all over the place. The ultimate answer, of course, was more cowbell! Juggling pins on the PIC freed up the I2C signals for the newly added ChronoDot and Frankenstein's monster was (nearly) complete.
Sub-adventure 37a in this saga required learning KiCad to get the schematic onto something other than taped-together scribble sheets, a visit to Dave's Hack-a-matic Board Layout Shack, and my first shot at a getting multiple boards to fit together.
The overall circuitry is straightforward as most of the magic is in the software and the stitching together of the various PIC modules:
The power section was interesting as I tried to incorporate the recommendations from the ST LM317 Data Sheet and lessons learned from working with some really good hardware designers. Mistakes are mine alone - but it hasn't smoked yet!