Hi David, thanks for the reply, that was my first thought too, however you will notice that unlike in the 1941 set
http://www.ebay.com/itm/Persia-Iran...381751590889 where the leaf motifs are just outside the oval in the middle, in my stamp the motifs actually touch the coorners, with the writing under them on the top and over on the bottom, rather than in between, as in the '41 set. That leaves my stamp still unidentified... :(