"Site Aviation was an air taxi company set up at Aberdeen Airport in 1973 to provide charter flight operations in support of the oil industry. With the rapid build up of air taxi business Site Aviation made the bold move to purchase three DC3 aircraft G-AMRA, G-AMHJ and G-AMSV from British Island Airways. 'HJ and 'RA were overhauled by Field Aircraft Services and repainted into Site Aviation livery, whilst 'SV remained in scheduled freight service with BIA. The first DC-3 G-AMRA was delivered to Glasgow Airport in January 1974 and operated one charter flight to Aberdeen. The following day all three DC-3's were repossessed by their former owner BIA. Struggling financially, the company ceased operations in May 1974 and the air taxi fleet was sold."
That photo is pretty over-exposed. There is a pic of the same aircraft post this date in the 'hybrid' Intra colours which show it much darker. The reg looks a bit better when viewed 'square on' and it is shortened a bit from real to avoid the tail texture map problem, but it is a 'square' font.