First, let me briefly introduce myself. I live in Malaysia and collect the stamps of the former French Colonies and overseas possessions. I have come across a puzzle:

According to the French Maury catalogue, on 9th June 1943 all eight stamps from the 1933 set showing views of Cayenne were overprinted France Libre. For political reasons these were withdrawn the following day but not before 300 sets were sold at the Cayenne post office and several had been used on mail within the country. The French Yvert & Tellier catalogue mentions this issue briefly but claims that only 200 sets were sold.
I have never seen this set of overprints offered for sale anywhere. Has anyone else?
Tonyfinch