I got it from a guy who sells them on Ebay. Goes by 2116cassandra. Nice guy. It originally didn't come with the backing plates or brake hardware, but after talking to him on the phone, he threw them in. It was an old set of brakes that needed rebuilt, but at least it was a starting point and free. It was set up for stock A-body width on the spring perches, and I think he charged me $35 to move them in because I have my springs moved in. He's somewhere out close to Carlisle and shipped it truck freight, took less than a week to get here to Southern CA.
