Here is the "Parts" projector with annotations as to most of the issues I could detect so far. In addition to the usual things that were corroded or stiff, it appeared somehow it got smashed in the front, bending the film stage components.
This was not a 'shipping' issue, as the paint in the film stage is worn off from the film touching the painted frame (which it is not supposed to do.)
One thing I want to point out. This "parts" projector is the later model with the easily-serviced three-belt system. One can tell because of the white (glow-in-the-dark, actually) lever.
The older 18-5 models with the red lever have a single, flat belt that is very hard to come by if it ever needs to be replaced.
So, this projector is worth fixing.