Thanks all.
Paul -
boot sales were, until a couple of years back, awash with the better stuff i.e with Rg. Nos. and diamonds, but those days have gone, unfortunately
I did find these beauties at the same carboot. Diamond mark for 1860's:
(https://lh3.googleusercontent.com/-coXDMMw2Y7k/TmUNioqTXOI/AAAAAAAAASU/j_Hp84Qesrs/s800/DSC_7581.JPG)
Christine - Thanks I will keep American In mind. That WorthPoint site really does my head in, I always end up there with something I'm researching only for it to tell me I have to sign-up for more info! Grrrrrrr - Anyone here signed up? is it another rip-off? I suspect so.
Rosie - I'm not sure what it is! All I know is that it's damn hard to photograph. I am veering towards a V but will give your suggestion the Google treatment - thanks.