Ouch! That's bad news.
As far as cutting windows in the inner panel and welding them back closed, that would be hard to get finished nicely, IMO. Granted, there are a lot of spot welds (around the window, along the belt rail and up the B Pillars), but none of them are overhead. All the ones on the belt rail are on vertical joints.
As far as the cab, with the rear rust you first showed us, and the damage you just mentioned at the windshield header and front posts, you might think about finding an original cab that's in better shape. I would think there are quite a few old farm trucks with acceptable cabs available in your area. That may be less work than trying to repair what you have.
Last edited by klhansen; 01/23/2021 1:35 AM.
