When raising the Beseler 45MCRX, the motor starts to struggle as it gets to about halfway - requires a push. It looked like it had been in a barn for a few years.

I cleaned it up, lubriplate on the geared rails, new motor belt, cleaned motor commutator bars, one brush is a bit shorter than the other, but length on both seems adequate. Rollers on carriage bars rotate with ease.
With the carriage out of the frame, when I turn the manual elevation control, it turns easier in one direction than the other. I opened the gearbox, cleaned out the old grease - gears look great - no nicks, metal shavings, etc. There are roll pins that aren't fully in - protrude just a little - not sure if that is normal or if they should be fully 'seated' - but I can't detect any slop in the mechanism.

Not sure what to check - just had time to fool with it to see if it could be improved.