Now the gauge works. Rubbed off the decals on the rear that delaminated from age and ordered a new repro set. Looked at the trans weep hole and for the 1st time during my many years of ownership; there was no oil coming out. My recent seals job corrected the leak(s).
Today I will attempt to get the boost gauge to work. Still waiting for a connector to replace the ECU coolant sensor one that has contact issues and messes with the idle.