If you can get back far enough from the damaged area to have good, clean metal the adhesive works great! It takes at least 1" on both the existing panel and the patch panel to apply the glue properly and not have the seam show up later after the paint is applied. I use my bead roller with the flanging dies to to roll the flange the edges of the patch piece. The patch must be properly formed and contoured prior to applying the adhesive so that you do not overclamp the piece and force all the adhesive out of the flanged area. I use either Cleco's or self-tapping screw to hold the panel in place till the adhesive sets. My personal preference is Fusor products, but 3M is probably just as good. As far as a source for the panels, don't know. On the old heavy metal cars like yours the panel is probably 18 ga., I'd just get a sheet of it, make some posterboard templates and cut out my own. It appears the doors are flat in the rusted area so cutting out a panel is no big deal. The bottom edge of that fender is going to be a bit more work!!!