I recently purchased this nickel and can't shake the feeling it might be a proof. The coin is slabbed as PCGS MS-66 in an older holder. The toning on the coin however looks identical to the milky toning that is common on the proof war nickel issue. The coin looks to be double struck making the steps unclear. Perhaps the doubling made it appear to be non-proof to the grader? I would love to hear everyone's input. Thank you for your responses.
The reverse is also showing moderate flowlining in the field below UNUM and through MERI. You would not see that on proofs.