cobra.ca, hope you have patience and $$, as Pastel Blue posted you'll need both. Problem is a short 2 year utilization of the Quadrajet on the 71 CJ Mustang, 70-71 Torino, sister Mercury cars, and the 71 Police Interceptor.
With a CJ, 4sp, and AC , the following is the info I have on your application. Ford ID# DOOF-F, Ford P/N DOOZ-9510-F, Motorcraft P/N CA-773, Rochestor #7040285.
Even though there were 4 different carburetors used originally, by 1975 they had all been replaced by one service unit. Ford ID# DOOF-B, Ford P/N DOOZ-9510-B, Motorcraft P/N CA-771, Rochestor #7040288.
As Pastel Blue suggested, just keep checking all the auction sites and Google your info and hopefully something will show.
I have had some carburetor work performed by Pony Carburetor's but understand they are now owned by Champion Carburetor.
http://www.championcarburetor.com/ Might be worth a try to contact them at the number they show and explain what your in need of and what they suggest. Good luck with your search!