Thanks for detailing the process, TNFOTO. I have a Mac, so I can't run Paint.NET, and the Mac equivalent, Pinta, seems to require me to rewrite the architecture, which I balked at. So I tried LiveQuartz, but they don't have the "auto-level" feature you mentioned.
Guess I'll be on the lookout for a Mac program with auto-leveling then. Hmm. How does that work? How does the program know that the sky is supposed to be blue, rather than the angry purple/yellow Topps so often turns it? Very interesting. (Don't get me wrong, I'm *glad* that auto-levels knows to fix that; I'm just not sure how it works.)
Thanks again. See, folks, I was just giving Scott a picture to practice on! The whole "It's Marty Keough, honest!" bit was just misdirection.
Really.

(Sigh.)