I kind of simplified the kinds of tools I used. Actually, I used anything I could find to scrape the crud off and then I slathered it down as much as possible with mineral spirits before painting. I used screwdrivers, scrapers, rotary and hand held wire brushes, dental picks... the places you have to clean will dictate the tool.
I have
PICTURES here if you want to see what I did. Firewall forward is the worse because of all the dried on grease and oil. Once get back past that there's not much to deal with.
I put down a total of three coats of Valspar (Tractor Supply) Gloss Black applied with an HVLP detail gun. Don't waste your time with aerosol cans... way too expensive and the paint is MUCH thinner than what you can apply with a gun. Thin the paint with the thinner recommended on the can.
It took me three days to accomplish... a Memorial Day Weekend. This was the first real "get in there and get something done" project and it changed my whole attitude toward the mountain of work ahead of me. After seeing the frame all painted I just knew I had to finish this, no matter what.
And I'm still slugging it out and a year more to go.