I have quite a few covers from the Touring Stamp Exhibition from the 1950's. It looks like they had a couple of shows a year, and had different cachets and special labels printed for each. This is one of my favorite ones, as it appears they have taken the second coins tete-beche sheets and overprinted them in both English and Hebrew. Other covers I have were used as receipts for the show entrance fee, and have a revenue stamp attached. According to the Mosden catalog, I am missing covers from only 4 of the 38 shows. These are Nahariya (6/4/50), Hadera (11/24/50), Even Yehuda (10/16/51), and Ramatayim (1/1/56).