Now that Mike has proven the 0.030" of tape method, I'd consider a permanent version of his method by some means. Perhaps a tape type fix of fiberglass tape and epoxy, sanded with engine running to true and smooth it. Alternately, epoxy steel alone applied and then shaped while soft with a specially made arched scraper. 0.030" at center is not a lot of material. There's probably some better way to make it permanent that I haven't thought of.