Update -- it has taken me at least 4 hours to clean the just the chassis.  Keep in mind this typewriter was remarkably dirty to begin with. I did several tests on different areas to see which one yielded the best results. I tried the following products: rubbing alcohol, toothpaste, Mothers Mag and Aluminum polish, soap and water, Flitz polish and WD-40. For applicators I tried: toothbrushes, cotton cloths, QTips, plastic scrubber pads and extra fine steel wool. My conclusion -- toothpaste and toothbrush and elbow grease yielded the best results. The chassis looks like new (with the exception of a few age related nick's and scratches).

Update: I decided to not do a full immersion cleaning. Instead  I used Simple Green in a spray bottle and focused on the basket area and the keys, followed by a very good rinsing and a rapid drying with compressed air. I also let the machine sit outside on a windy sunny day to air dry. The outcome was remarkable. Prior to this cleaning all the keys were either stuck, or sticky. Now, all they keys move very easily.

I did some minor adjustments, cleaned more internal parts with Q-tips and dental picks, did some touch ups, reassembled the chassis, and presto, I have a clean, functioning 1950 Smith Corona Silent. I am quite pleased with the outcome. This was a great learning experience.

Phil_F_NM wrote:

I am assuming that when you say chassis you are meaning the painted metal body. The chassis would usually denote the actual mechanical bits under the body. Did you take the body off the machine?
Phil Forrest

Yes, I meant the painted metal body. (I'm still learning the correct nomenclature). I removed the body first and  cleaned it with toothpaste and tooth brush. I found this worked best to remove the greasy layers of dirt. The internal workings (mechanical bits) were cleaned as I described above.

Anybody know what the original dimensions on those washers were? I wonder if McMaster has them. Might be handy for this and other projects.