Can try the various part numbers in ebay or ask your local store (if there is one) to see if their warehouses have them.
That guy from around NY, screen name mobileparts, he may have an good pair used or unused. He often goes to Carlisle.
Last time I put new shoes on my Barracuda, I had East Coast Machine turn the drums. Who knew these would become rare parts?
I've held onto the disks and hubs but I'm sure I scrapped a few drums...