
There were mummy's walking around when that was built...lol

Since you've cleaned the Futurelogics' golden-aged rollers and belts, it sounds more like some IC component on the board inside has gone out of specs... probably age-related.
Could be a capacitor, a transistor, an end of paper optical sensor, anything.
If yours has the blue lever, it must be in the up position to pinch the rollers to grab the paper.
It sounds more like the end of paper sensor is out of whack though.
Have you looked inside at the circuit board?
Yours is Netplex comm....not too costly for a working, tested replacememnt.
Here's a link to an ancient manual...>>>
https://www.manualslib.com/manual/2594374/Futurelogic-Psa-66-001n.html