Updating in case someone else runs into this issue, and a bit of a "watch out for" note.
Had the GG-1 taken apart and started to look at the wiring harness after checking wheels, rollers, trucks, worm gears for cleanliness and continuity.
While I was tracing wires I noticed that a number of the wires appeared to have broken through the original heat shrink in a number of the joints. Now I don't think this was the cause but I found it worrisome anyway. I removed all the heat shrink, re-twisted and re-soldered the wiring joints.
Followed the main powered wires from the trucks, joints/junctions back to the main board and re-soldered each of the 4 main input wires as well.
Unit seems to be running well now.
Thank you to all that replied for the help.