Natal 1879 Uncancelled 6d Letter from Durban

1879 Envelope bearing uncancelled QV Chalon 6d violet ovptd POSTAGE (SG 83). Backstamped Durban cds 17.6, a very early use of the Durban cds (Hart type K1). Traces other arrival cds in red. Roughly opened top left. The envelope is addressed to Lord Conyers in London, possibly being from his son, who died in Natal three months later at the age of 17. Minor imperfections.