Front drum to disk brakes conversion.

I removed the calipers from my (one-owner) '70 Swinger about 4 years ago. Pistons were stuck so bad nothing would take them out. Two years later, my plans included upgrading to the larger bolt pattern using all parts from '73 Duster (340). Sold the calipers to friend in Alberta for his project. Haven't been in touch with him since then. He had planned to use the calipers as 'cores' via exchange. While I still had those calipers, one of my options was to refurbish them and fit onto my Signet, so I had ordered the replacement pistons and seals from R.A. Now, a couple years later, still have those rebuild parts in orig. packaging. I have receipt somewhere but figure they cost near $60. (U.S.). I can sell for that - including shipping. I think they are the Centric parts.