Here's a denarius of Faustina struck over a previous issue. Let's see your overstrikes or anything you feel is relevant! Faustina Sr, AD 138-141 Roman AR denarius; 3.83 g, 18.2 mm Obv: DIVA FAVSTINA, draped bust, right Rev: AETERNITAS, Fortuna standing left, holding globe and rudder Refs: RIC 348; BMCRE 360; Cohen 6; RCV 4577. If I rotate the reverse 90 degrees counterclockwise, you can see a throne and what is likely a cornucopiae beneath it. Coming down from Fortuna's face is a roughly spiral-shaped vertical object I think is a goddess's shin: I postulate it was a CONCORDIA AVG issue of Sabina: Another example:
The detail in her hair... that’s Mint State quality! Always my favorite part of her coins. Beautiful collection as always!
I'm not convinced by the supposed undertype, RC. Could just be die faults, in my opinion. If overstruck on Sabina, one would also expect remnants of her portrait to be visible on the obverse.