Interesting find!
I have doubts that this is the OMM. Your mm looks too far west for the S/D, and I don't see the tell-tale die marker (chip at 11 o'clock of the inverted "V" between Lincoln's vest and coat) on your pics. You may want to see the chip pic on coppercoins.com and examine that area for the chip.
That said, there are Avogadro's Number of S/S RPMs for 1946-S. At first glance, your coin looks fairly close to RPM-005 (Wexler's WRPM-003), and that variety has quite a few die markers that could rule it in or out. Definitely check coppercoins.com and doubleddie.com (John Wexler's site), which have excellent pics of most of the known RPMs.
I have doubts that this is the OMM. Your mm looks too far west for the S/D, and I don't see the tell-tale die marker (chip at 11 o'clock of the inverted "V" between Lincoln's vest and coat) on your pics. You may want to see the chip pic on coppercoins.com and examine that area for the chip.
That said, there are Avogadro's Number of S/S RPMs for 1946-S. At first glance, your coin looks fairly close to RPM-005 (Wexler's WRPM-003), and that variety has quite a few die markers that could rule it in or out. Definitely check coppercoins.com and doubleddie.com (John Wexler's site), which have excellent pics of most of the known RPMs.

























