These are the labels from Air Ceylon.
Air Ceylon was Ceylon's (later Sri Lanka's) national carrier, commencing scheduled operations in December 1947, and was fully state-owned. It ceased operations in 1978 and was replaced by Air Lanka. (Wikipedia).
Year: 1949, Gummed. Günter Mair's catalogue no: - SLK-B-1, rouletted HU, VL, blocks with 25 sheets of 1 pair tête-bêche, blue/orange-red/white, 3***
Year: 1949, Gummed. Günter Mair's catalogue no: - SLK-B-1, tête-bêche.