I can only illustrate two. The first is an extraordinary item posted on the Ryazhsk 61 Vyazma TPO on 24 10 20 and addressed to Belgium ( a country which does not appear at all in Epstein's 142 item inventory!). It is franked at the officially correct 5 rouble rate for an ordinary foreign letter, using an imperforate 5 kopeck revalued x 100. Censored in Moscow 27 10 20 ( and opened through the back flap), this letter received a BRUXELLES - BRUSSELS reciever cancel on 8 XII 20.
If Soviet postal history was taken seriously, this cover - October 1920! TPO! Belgium! Ordinary letter! - would be a 1000 dollar / euro / pound item though minus whatever discount is due for the idiot Biro marking, bottom right of the cover front.