I'm now ready for a VIA!
I pulled out a blank PCB and loaded it from scratch. I have no bodge wires on the board (the previous build had supplemental VCC and GND runs on the backside). I have address decoding running from the GAL PLD.
I'm quite happy at this point. :)
Pay no attention to the typo in the video, lol.
After I get a VIA running (with an LCD), I need to get the extended RAM working and improve the decoding logic to use VDA/VPA.