1932 (May 14), Strasbourg Exhibition Flight cover from Sofia, addressed to Paris, franked by Rila Monastery complete set of three, tied by red special Sofia date stamps, part of postal receipts seal and Paris ''23.V.32'' arrival marking, mostly VF, Est. $100-$150 (Image)

1969, European Hake, 1st olive green and black, top and bottom margin vertical strip of five imperforate horizontally, full OG, NH, VF and a spectacular item, Est. $300-$400 (Image)

1970, World Soccer Championships in Mexico, 1st blue, black, red and yellow, bottom right corner sheet margin single imperforate at right, full OG, NH, VF, Est. $100-$120 (Image)

Postage Due stamps. 1884, Numerals, 5st orange, 25st lake and 50st blue, complete set of three with lozenges perforation, large part of OG, VF and scarce, each stamp with experts' signs, C.v. $970 (Image)

Zeppelin Flight. 1929 (October 16), Balkan and Silesia Flight cover from Sofia to Pforzheim, franked by 6L dark blue and pale lemon, tied by Sofia date stamp, the same day Zeppelin onboard marking, four-line cachet on reverse, mostly VF, Sieger #42-43 var, Est. $400-$500 (Image)