I got this today from ebay England.
First, the serial # is on the smooth band above the TTO knob: F326335, 1918.
It looks like a repair code, but not like one I have. Also, note that the inner shaft has the Pat # on the end. I didn't notice that till I saw this photo!
The Gillette logo is stamped on the inside of the base plate and on the inside of the guard.
And the bottom of the case, nothing special, but as an aside, does the Pat information on the bottom of the case help date?
I got maybe 10 or so Single Rings and this is the first of this kind. I figure somebody went nuts on the manufacturing floor and it got out the door.
Any other ideas?