Out in Metairie there are 2 places, Puglia's and Chag's. They both have 45-70's, 444s and some 44 mags for the LA and MS 'primitive' seasons. They really don't have much else except an occasional youth size 243. Some of the pawn shops out in Metairie or the westbank may have more interesting stuff. (The city itself does not have many gun shops anymore.)
Perhaps in a few years as folks begin to see the versatility/potential of these 'primitive' weapons there will be more handi-holics and stores that cater to them around here. I just got my first accessory barrel (12 ga with chokes) recently and have not fired it yet.
I will be in California starting Monday, or I would have wanted to meet you.