1969 C-10 step side

[hilltop55]

Looking for some advice on a possible purchase. I have a local man who is selling a 1969 Chevy SWB c-10 stepside, 6 cyl, 3 speed on fllor. Bed floor rails rotten, door, rockers, floor are bad. The worst part is the roof line inside top near the pinch weld is rusted all the way through. Is there a re-pop of this piece and if not, how hard is it to repair. I am a decent welder, not great. thoughts?

Oh by the way, I think I can get it for 500 bucks. It also runs but the rear axles are out. Trucks a mess!