Till so far the cargo vessel in the background of this stamp was given as one of the Ellerman Lines, thanks to Mr. Robert Harm in South Africa who contacted the designer Sheila Nowers who gives:
The ship depicted behind the ELAND is an Ellerman and Blacknall cargo vessel which I adapted as a background to the main subject. Truth to tell, I have since discovered that the ship in question was photographed in the late sixties in Cape Town harbour, whilst the ELAND was operating in Port Elizabeth and scrapped in 1962.
The following comes from Mr. Harm.
He gives the background photo appears on page 27 of a book “Maritime South Africa” by Brian Ingpen and Robert Prabst, and Brian has confirmed the name of the ship as the CITY OF GUILDFORD.
Built as a cargo vessel under yard No 1883 by Swan Hunter & W.R., Wallsend for the Ellerman Lines Ltd.
27 June 1957 launched as the CITY OF GUILDFORD, three sisters, she was the first of this class built for the Ellerman Lines.
Tonnage; 4,954 grt, 2,517 net, 7,760 dwt., dim. 132.28 x 17.98 x 7.62m. (draught)
Powered by one 8-cyl. Clarke-Sulzer diesel engine, 5,040 hp., speed 14.5 knots.
November 1957 completed.
1979 Sold to Eurydice Mar. Co. Ltd., Greece and renamed EURYDICE.
1981 Sold to Chimadea Mar. Shipping Co., Greece, renamed MIGHTY SPIRIT.
1984 Sold to Wonder Shipping & Trading Co Ltd., Malta and renamed NIRAV.
1984 Sold to shipbreakers in Chittagong, Bangladesh, where she arrived on 17 September 1984.
South Africa 1994 1r15 sg847, scott889.
Sources: http://www.miramarshipindex.org.nz Merchant Ships Vol. VI. Register of Merchant Ships completed in 1957.