[R-390] Black Anodizing?

[Kenneth Arthur Crips]

Here is a listing of places that do this kind of work.
 
http://www.aluminumanodizing.com/

You might check out local Gunsmiths to see who they use for this. 
They deal with this short of thing all the time.
 
                                              Ken

Kenneth A. Crips, W7ITC, Cheyenne,
Wyoming. with The Chew Crew; Beezie,
Chic', and Cowboy, Irish Terriers who
are Red House ninjas with 10th degree
Black belts in Bed Fue, Mooch Fue,
Chew Fue, and Con Artist Fue