If you really wanna get into the cowl, you are going to have to cut the top away to get to the rust... once you do that, the only way to fix the rust is to cut it out and weld a new piece in the original spot. Keep a good eye on the cowl for the next couple of days after because if you didn't get all of the rust, it will start to bubble. If then, grind down bubbled spots and respray...

military_stang