The problem is that you might need 8 and then it becomes expensive. I have a set of bare calipers that require all 8 of the pucks plus the rebuild kits so I’m not sure it’s worth buying all the parts to rebuild them and then offer them for sale.
I have a set from my '68 cuda. I converted to the '73+ 11.75" rotors/calipers so I don't need them. And I have many extra pistons for the calipers, some are useable. PM if interested.