Help With Identification

This is a $20 Probate revenue stamp. R98C and R99C (from what I see) are both perf 12. This stamp is perf 10. I measured it several times with two different gauges, so am confident with the 10

I have looked on a few online catalogs and cannot find this stamp with perf 10.

Any help would be welcome.

Those perforations do not look kosher. I await further comments, but it appears to be some sort of re-perf or hmm?

These are not authentic perforations. The stamp has been fraudulently perforated on all four sides. It may possibly be a perforated photocopy of the stamp (from an auction catalog?).

What is the paper like, it appears to be bright white? Does it appear to be of the time period of the stamp? Is the paper or design glossy? Can you post a photo of the back side?

There is no cancellation, which is not typical for this stamp. Possibly a poorly perforated proof?