I have a post card from Hallatrow near Bristol on 21st April 1886 to Barbados; it was not delivered and was returned to Hallatrow on 23rd July 1886. It bears two ship letter marks; the -circular "Ship Letter London C.July 22 86" in red and an oval mark "Barbados 29 June 86 Ship Letter" in black. I have not seen another example of the Ship Letter mark and should be very glad to know more about it.