Ross-
You can buy that panel for less than $100 from most suppliers (LMC, Jim Carter). If you are 100% set of fixing the one you have, then go forth with it, but in my experience, by the time you buy a "rust convertor" product (that 99 times out of 100 isn't as good as it was advertised to be) and spend all the time to strip, repair, fill, prime, and paint. You probably would be further ahead to just buy the replacement panel. It's your call though.
