Thank you for your opinions as I value them highly.
Got to examine the coin in person. You do need good light to 'dig' through layers of dirt and haze to get to the surfaces. I would say it was struck as proof and was mishandled in a manner that is similar to the other Russian proof in the EPN sale, which managed to get a
PF grade from NGC due to pretty well preserved reverse.
Since EPN kept these coins in pre-WWII envelopes, I would agree the coin is likely to have originated from the 1936 EHR Green sale. Therefore, proper grade should say, 'Proof: impaired by a celebrity.'
To put the last nail into the coffin, have you gentlemen handled this variety? Was it business, or proof? I am only familiar with the proof from the Goldberg auction over a decade ago.