I went ahead and finished up the main patches for the engine bay (another one on the shock tower and one on the very front of the frame rail) and repainted it. I didn’t make it perfect because I’ll need to redo it whenever I take care of the rest of the front end rust. I basically just sanded the old paint down a bit and masked things off with aluminum foil. Then I sprayed about 2.5 coats (I ran out of paint and didn’t worry about buying more) of semi-flat black Krylon Rust Tough Enamel. It looks okay considering; it’s at least better than it was.
I also cleaned up and repainted part of the underside of the cowl and the firewall on the passenger side. I didn’t take any good before pictures, just a couple after paint.