I found a rather poor patch job completed in the same method as the old floor patches. a smattering of rivets were procured, along with some galvanized duct-work metal, and the weekend warrior broke out the tin snips and rivet gun. the patch job was then iced with a slurry of undercoating tar to hide it from any suspicious mechanics. I broke out the cutoff wheel and went to work, slicing out the badness where necessary.
I had to make a few cuts so i could bend the metal to fit the frame shape, and then patched the cuts back up with the scrap metal and some welding.
Some test fitting and then clamping allowed me to line the whole thing up and weld it in place. Although the rusted portion was near the back, I ran the angle iron the entire span of the frame, thus making it a double purpose patch and skid-rail for off-road use. I was more or less pleased with the patch, and it should allow the vehicle to pass certification. It's amazing how many problems I didn't know about when i bought it (I may have waited and bought a better one had I known, but that's neither here nor there at this point).

