Cover franked with single 1970 15c 'Kariba Dam' QE2 issue (SG 447) tied by SALISBURY machine cancel. Addressed to UK with boxed 'STAMP NOT VALID TO PAY 3/6' cachet in green on front with added Great Britain 1959 1/- ochre & 2/6 purple on yellow 'Postage Due' issue (SG D64/D65) tied by LONDON cds. Nice red on white 'Southern Rhodesia Stamps. The government has announced that the stamps issued in Rhodesia of the kind used on this postal packet have no legal basis. The packet is accordingly surcharged' label on reverse.