Polar travel 1931, stage Friedrichshafen Malyguin, letter from Friedrichshafen 24.7. with 4 RM Polar travel, alongside one-line cancel "Special Delivery" and reverse pasted up 10 C US special delivery stamp as well". INTOURIST . " three straight line cancel, via Malyguin 27.7. and Washington 3.9. to birmingham, Ala. 4.9.