Here is today's oddity. I really appreciate the experts taking the time to help me learn the hobby. As I sort through several hundred 37/41's, I notice stamps that just don't seem to fit the mold. Perfs are my current albatross...
The attached image is 1200 dpi. I have checks using the gauge, and digitally - they both show 12.2 x 12.4, which seems very close to K65 x K64 (12.18 x 12.38).
The paper is horizontal, ribbed/wove, so that would possibly indicate a 37? There is no apparent PD (possibly one at 3 o'clock in the border?)
The size of the oval seems to be within limits for other stamps I have measured, so it shouldn't be a paper deformation issue.
Is this a normal perforation for a 37/41 (which I assume this to be)?
Here is the front
..and reverse showing paper
Thanks for any advice - Chris