My Ebay Single Ring came today, I have never seen anything like this one. It has the serial number on the barrel of the handle (F251016) diamond and arrow logo under the cap and on the top of the head.
The description on the bottom of the box talks about guineas (sp?). I would guess that it is a US made Single Ring for the British market. Just a guess though!
Edit: Doesn't say Made in US anywhere. Could be a British made razor then. Another guess!
It is definitely British. The 1902 British patent 28763 is for the "Improvements in or relating to Safety or other Razors".