Pretty sure (but not positive) that is a Single Ring. It can be difficult to tell the early Big Fellows (Old Type head until '21) from a Single Ring without a point of reference for size in a pic. The Big Fellow is MUCH bigger, fatter, etc. but proportionally so. The proportion difference to focus on (in a pic) is the relation of the head size (which does not change) compared to the handle (I've scaled a few on the screen when unsure in eBay pics, but you've got to watch perspective in that case).
For comparison, here are a few pics I took of Big Fellows compared to Single Rings. Bottom shot is my 1905 Double Ring, just because you mentioned them in the thread title (note the extra ring between the head and the handle tube).
Thanks for the info. Mine appears to be a single ring. I was a Luddite and manually sniped that for about $12.51 tonight. I just checked the Date Guide, and it appears to be from 1918.
Sweet! I love the Single Rings, and they often come as bargains (lots out there). I got one in a Gem case, advertised as a Gem Damaskeen razor. Serial number listed in ad, showed it to be from 1910. Final bid $12.87 shipped. That's it in the third pic, far left. That case? The same week, I spotted this 1910's case with a Gem razor in it . That was +/- $25 IIRC.
And BTW, these things shave great! Used the middle one today (1905?), and I'll be shaving with them all week.
If you're going to shine it up, have a look at the method AsylumGuido suggested for this Bulldog (scroll to 13th post). For more information on that process, see this article.