Good question...
I'm not very much in the know on that but I reckon that all the old British razor manufacturers (in Sheffield, for example) have gone bust a long time ago and, unlike Dovo or Wacker in Solingen, haven't resumed the production of razors. I belive that Wade and Butcher are still making cuttlery but I reckon it will be difficult to find a brand new British razor.
However, if you want to buy a vintage razor there are plenty to choose from if you are patient enough to find them. Or you could just go to the classifieds here and see what our brothers in shaving have in stock for us...
My two pence!