Well... I was thinking of anodizing it yourself, of course. It's not that difficult - prol not worth the setup for just one part, tho.

Aluminum "takes" soot pretty well - I think it might take better if you swab/scrub the inside of the chimney with alcohol right before you fire it off the first time. Burnish it with a dry cloth after each use and it should get a good hard coat of carbon over time. However... since you're thinking about using it indoors, let me point out a probable side effect - when you use it with an "odorless" fuel indoors, you'll get a little aroma from fires past - not unpleasant if you keep the loose soot and resinous stuff wiped out. My old aluminum snow-melting kettle smells like Alaska whenever I use it on the gas stove indoors... it's pretty black on the outside.

Hope you have time to play around with the kettle this week.