That all sounds good. There are a couple of reputable outfits that rebuild mags. The one I've used a couple of times is Mainely Magnetos to rebuild an Eisemann and an American Bosch, both two cylinders, but I know he does four cylinder mags too. They come back brand new. You send him what you have and he replaces what needs replaced, and will add any missing parts. You can't go wrong fitting new bearings to everything you replace, such as that pinion.
The Twenty is a neat tractor, I did major work on assembling a nice wide gage Big 20 from a collection of parts during the onset of covid as I had time at home. I have lots of parts if your in need, Were ready for questions, bring em on.
I saw another post on here about Mainely Magentos also. I plan on contacting them this week to get that started. I was concerned that gas had been sitting in it over the years, but when I looked inside the gas tank it was bone dry clean. Someone must have drained it at some point, which made me happy not to have to deal with gas varnish. Not sure about the carb yet.
It was probably me that mentioned that magneto shop but there are others that people sing the praises of. I just can't remember what the others are called but someone here might. For your tank, just need to verify that the fuel flow out of the outlet is adequate and sustained, and that it doesn't leak.
Plan on getting it loaded up and stop at the National Pike Show Brownsville PA May 22nd 23rd on your way back to Maryland. Would like to see it. You never know , there maybe a mag in the flea market that will work.
I will have to look at if I can work the National Pike Show into my trip. Will depend on work timing availability. I like the idea. I attended that show in 2016(I think) when ACMOC had the event there. Walked around and took a bunch of cat pictures. Was a great show.