Hmm, interesting.

It's too bad you can't trace the source to the breeder to find out if he was born that dark, or if he underwent a color change at some point. To me, he doesn't really have that Dirty Joe/IMG/"presto-chango snake" look to him, but I've seen it happen with my own animals enough times now to question if there's a metabolic (and not genetic) cause whenever I see an especially light or dark animal.

Otherwise if you don't get something neat in the first generation, I would think your best bet would be to breed back his female offspring to him to see if it could potentially be a recessive hypermelanism overlaying the cinnamon trait. He does kinda remind me a bit of this type of hypermel, though, which evidently hasn't proven genetic:

http://ralphdavisreptiles.com/collec...all_python.asp

Doesn't hurt to try, though!