Discounting the unknowns for the moment. Total conjecture, if it is NR, at a stretch of the imagination, it could be Nichols & Raimund a manufacturer of belt buckles, however the drawing I have seen of their mark in a circle is different, an N and R sharing the last upright stroke of the N. But we know that companys changed logos. Or is it RN ? Don, you mention the posibility of it being FNR. Do you happen to have a clear close up of the mark? Ah well, fun to research. I also hope something comes to light. --dj--Joe