[FOR SALE] Original 1971-76 Duster Master Cylinder Power Disc brakes

Original 1971-76 Duster Master Cylinder with Power Disc brakes, casting number 3580121, $50

Located in NJ

My crib notes show that casting has a 15/16" bore and was originally used for master cylinder 3680 112. If correct, that was for A-bodies with floating disks and power assist, 1973 - 4 and ? Looks like I got that from Paul Herd's book, so take it for what its worth.