rust repair at wheelwell

Hello everyone. I have to repair a rusty section of the frame rail pocket at the rear fender wheel well on my 5 window. Does anyone make a short repair section for this? I'm sure this is a common area for rust damage. It looks to actually be two pieces. One on top of the other. The top piece has a step stamped in it, and would be very hard to hand form a repair piece. The rear floor pan welds to one side, and the fender well welds to the vertical side. I have a new floor pan and don't want to leave this section in place unless I can't find a replacement. Man, these things rust in some of the darndest places! Thanks in advance for all replies.