RSFSR Zag:SU-PE16 - surcharged in black typo - 25 k. on 300 РУБ - Further surcharged with a 10 k black hand stamp.
Overprinted in black typo -
КОНТРОЛЬ СФА ЗАГРАНИЧНОГО ОБМЕНА
"SFA CONTROL OF FOREIGN EXCHANGE"
Rough perforations added.
This is a revenue stamp which was used to pay a tax on stamp exchanges carried out through the Soviet Philatelic Association. It was affixed to incoming or outgoing envelopes containing stamps and it would receive a violet or black rectangular cancel.
Listed under "Gebühren für Briefmarken-Tauschsendungen" (Fees for postage stamp exchanges) in Michel, "Timbres d'Usage Spécial" (special usage stamps) in Yvert and "Exchange Control" in Barefoot.
