PRETORIA TYPO PRINTING LOWER VALUES "CONTROL" PAIRS ON LETTER: 1929 Registered letter from Cape Town to Johannesburg franked with 1929 4d & 1/- Airs together with Pretoria Typo Printing ½d, 1d & 6d each in lower right marginal CONTROL PAIR proving characteristics of PLATE 2. All cancelled by Cape Town cds's of 24 AUG, Cape Town registration cachet and Cape Town backstamp. Exceedingly rare piece with the marginals markings thus. With the combination of the newly issued Airmail stamps applied, this cover was likely intended to be carried on the Union Airways inaugural mail service flight from Cape Town to Johannesburg on 26th August.
