I don't restore Mustangs,Only the one that we own. I didn't find it necessary or cost effective to buy a spray gun or a compressor(I do own a compressor now). I done some research some 10+ years ago to what would be the best and closest engine bay semi gloss black I could use. Back then, my initial intention was occasional driver,which is what exactly it was at the time. And after all my research, I came up with Eastwood semi gloss black, and just hoped that it would be exceptional, at least for me.
The Eastwood paint turned out better than I would have anticipated, so thats the way it stayed, even while I graduated into the concours "driven" class.
Anyway, myblue67, I would sand it. you don't have to go down to the metal. If you can see visible runs in the original paint,LEAVE THEM, thats the way it came from the factory.....Good Luck with your Mustang