I don't know what's going on Norm, would'a swore on a stack of bibles I answered your PM. Anyhow, my answer, in a nutshell, was learn to live with it or else send it back.
You'd need more than a MAPP gas torch to straighten a blade that size, not to mention what you'll be doing to hardness/temper. Going to have to remove the blade from the handle entirely, bring it up to forging temp, and use a hammer and anvil to true it up. 'Course once that's done, the blade would have to be re-hardened and re-tempered.
A less troublesome "fix" if the "S" curve you're describing ain't too dramatic, would be to camouflage it somewhat with some decorative filework along the spine ala Sgian Dubh/Scottish dirk. Ain't hard to do (practice on some scrap metal first), and the spine should be soft enough to file easy. Could be rather groovy.
Sarge