SA: 1931 Imperial Airways special Springbuck envelope franked 1/- carried on the inaugural Christmas Flight to South Africa. Wilton Road dispatch cds 9 DE (this was the sub-post office serving Imperial airways and only mail posted there and at Croydon was carried on the first leg by the "Heracles"; bulk mail had been sent ahead to Paris by rail) and on reverse Johannesburg arrival cds 21 DEC 31, Stanley Gibbons handstamp. F-VF, scarce, only 75 letters carried the entire route to South Africa.
