Bit hard to find cover featuring King George VI Stamp overprinted with "M.E.F.," which were originally used by British forces occupying former Italian colonies, particularly in Eritrea, and later in Libya (Cyrenaica and Tripolitania). What's really interesting, though, is that this Active Service Cover offers a seldom seen combination of; King George VI MEF GB Stamp Plus South Africa War Effort stamp &  Cancelled by Egyptian Pre-Paid No 71 cancel, which was issued exclusively to South African forces, using Army Post Office 29, which at the time was based in Cairo, Egypt.