Joe:
If you want to leave this machine as original as possible, you don't want to touch a thing.
On the other hand......................
If you want to just clean-up the castings, you can wash them with a very mild soap and water.
But, even with this light process, you are liable to loose what very little paint that is left. It is
really in the "no paint" zone, in which you may want to do a "semi-restore". It will have new
paint, but won't be all 'glitzy & shiny', like a new machine. This is something that I tried-out
on a couple of different slots, several years ago. First, I did not bead-blast anything. Just
cleaned the castings with soap & water, and a toothbrush, to get in all the corners. All of the
high spots were wet-sanded with 400, and fine steel wool. Painted the appropriate colors in
the low areas. Wipe off any paint overlap with thinner, after dry. The final finish, is a coat
or two of Dull or Satin clear-coat spray, which is available in a rattle-can. If everything is
done properly, it will come out looking like a 'real-nice-clean-original', not restored.