You seem to have a handle on the cowl repair. Pretty much, remove windshield, grind all the spot welds out of the bottom part of the pinch weld, and cut the outer cowl off and remove it. Not for the faint if heart, but plenty of people on here have done it and posted up how to do it. If you do a search, it might come up. I've never had any luck with the search feature though, no matter how much the mods brag about it. I think it blows.
Aside from that, WHERE is the tune up on it? Have you checked the point dwell? The timing? Put a vacuum gauge on it? Those compression numbers say you have a pretty healthy engine.
