Major rust in "A" pillar, repair ideas needed ...

[Evilclone13]

I have a 65' GMC that has major rust in the "A" pillar that is in need of repair/replacement. I'm not having any luck finding a patch piece for this section (which I didn't expect to find). That being said, I know most people will recommend swapping the whole cab out with another donor, but I really don't have access to the equipment you would need to swap out the cab.

If you were going to tackle repairing this section of the cab, how would you go about it. I have access to sheet metal (not sure what thickness to buy?) and I have my own gas Mig, plus hammers and dollies. I've never repaired a body section like this, especially one that has this kinda of curvature and structural importance.

Any and all advice is appreciated ... Thanks!