24th December 1891 1d spiked Post Card from Colhester (Winch Bros) to  Johannesburg showing a very fine strike of the scarce POST CARDS TO THIS ADDRESS CANNOT BE FORWARDED handstamp with London c.d.s. alongside. This cachert was used on U.P.U. post cards addressed to countries that were not in the Union, Transvaal did not join until 1893. This card is illustrated on page 419 of “Southern African Mails” by Brian Trotter RDP