Being a collector, we use the old manuals to remind us of every pre-1964 British sign, but every now and then one isn't there and we need the memories of those around before us who can fill in the gaps. Oddly there is no picture of the one way street signs at the start of the roads (now a white on blue arrow) and have a single one online which has an arrow and one way street next to it here in 1968
http://www.flickr.com/photos/thedouglascampbellshow/4626450639/
As they vanished early I can't remember them either, and found this on a private road which has the holes for pole mounting which implies it wasn't custom made as the wall mountings have been drilled specially. I do know many old signs had two or more versions as well so just because I've seen one genuine one doesn't mean mine isn't as well, so minus an official illustration if anyone remembers if this was a standard issue on public roads I've got one more type in the bag and so far the only one in Britain either way.
http://www.flickr.com/photos/satguru/9145545616/