Willams Grand Prix Pinball Restoration

Okey, I've read the PinballHQ EM repair guide, and it's pretty strict on lubrication:

Electro-Mechanical machines, for the most part, do not require any lubrication. Most parts run "dry". Far more damage can be done to a machine by over-lubricating, than by under-lubricating. As a rule, if in doubt as to lubrication, don't do it! ... The only parts that will require any lubrication are metal-to-metal moving parts. There aren't very many in an EM game. So keep that lubrication in the tool box and away from the game.

So far I've stayed clear of any oil, but after going over some of the stepper units and drop targets in the machine I'm starting to wonder if maybe these classify as "metal-to-metal" moving parts. Small shafts that are supposed to move without any friction are very slugish and almost stuck, and I'm not sure how to fix this. They seem to have been oiled some time in the past, but that might have been a mistake? So, should I oil these parts, or should they be cleaned and sanded?

I'm spesifically talking about the drop target mechanical joints marked in the picture below:



And the shafts in the stepper units:



Oil, or no oil? And if no oil, what to clean it with to remove the old oil and how to make it's movement smooth and without friction? I guess that is the question.

RGP post here