That does look like an RPM, but unfortunately it is not,it's just a MD,flat and shelf like doubling where the device has actually shrunk in size.but you already scored nicely on your Six 1952-dime RPM's

Note the very nice die crack with a chain of die chips on the Bust extending to the 1 of date, and another one on top of the head and the Eagle's right wing ( viewer's left)
