AB Aerotransport (ABA) was a Swedish airline, that is today part of the SAS Group.
ABA was established in 1924 under the name Aktiebolaget Aerotransport by Carl and Adrian Florman. The first flight was on 2 June 1924 between Stockholm and Helsinki with a Junkers F.13 aircraft. The aircraft, registered as S-AAAC and later as SE-AAC, is now on display at the National Museum of Science and Technology in Stockholm. In 1925 the company started a route between Stockholm and Berlin in co-operation with Lufthansa and a mail route between Stockholm - Malmö - Amsterdam - London.(Wikipedia)
Year: 1945, Gummed. Günter Mair's catalogue no: - SWE-B-1, rouletted H, booklets with 4 strips of 4, blue or grey-blue/white, 4****