Dan,
I have cleaned and sharpened over 200 saws in the last few years. This is the
process I use for cleaning the metal parts.
For brass screws and medallions: Soak them overnight in a 1:4 solution of liquid
laundry soap and water. I use Tide Free and Gentle, as it seems to work better
than other products. The laundry soap will clean away oils, dirt, and much of
the oxidation without leaving an over-polished surface. The final cleaning is
done by brushing with a fine brass wire brush, which leaves a clean, soft finish
that is not too shiny.
For saw plates: I recommend wearing gloves to keep your hands clean, as the
process can get quite messy. First, carefully scrape away the majority of the
rust and dirt with a single edged razor blade or a sharp chisel. Round over the
corners with a fine stone so they do not dig into the metal and cause scratches.
Next, use 400 grit wet-or-dry sandpaper on a hard rubber block to sand the
remaining rust from the plate. I like to use Simple Green cleaner to lubricate
the plate. It is safer and not as hazardous as mineral spirits. It also smells
much better. I generally stop at 400 grit after the plate is clean, but you can
go to 600 grit if you'd like a little more polish. The next step is to rub the
plate with a burgundy Scotch-brite pad, which gets down into the grooves on the
surface of the metal and pulls out the remaining dirt and rust. The final step
is to polish with Autosol metal polish on a cotton cloth. Finish up with a coat
of paste wax. By the way, I never use Evaporust, citric acid, or any other
aggressive chemical on saw parts. I do not like the finish these leave and some
may actually cause damage to the metal.
Here are a couple of before and after shots of a Bishop rip saw that was cleaned
using this process. The handle was lightly sanded and finished with Tru-Oil.
https://flic.kr/p/PRzRCz


https://flic.kr/p/QUFdsn


Have fun! It is satisfying to use a saw that has been saved from the scrap bin.
Bob PageIn da U.P. of Michigan

    On Tuesday, April 23, 2019, 7:47:46 AM EDT, Dan Beck 
wrote:
 
 I should have mentioned this in my first post- I spent several hours on the
Disstonian Institute site trying to ID these saws. I think I have the first two,
but could not figure out the last one. None of the etchings are visible enough
on any of the saws to help. Maybe the handle on the third saw is not original?

Cleaning question- when cleaning and restoring planes, I will often soak the
plane iron, cap, etc in a citric acid bath overnight to remove rust. Could I do
the same for the saw plates, nuts, and medallion on these saws? Or, could I use
Evapo-Rust? I’d prefer not to use mineral spirits (but I will if the general
consensus is that’s the best way to clean and de-rust).

Thanks, 
Dan