Authenticating Coil With Blind Perfs

So I came accross an interesting pair. I know expertizing old Wash-Frank coils is dangerous at best. I would be suspicious of this pair but wondering if the blind perfs make it more likely to be genuine - would a counterfeiter leave them in (I guess if I am asking they might). Any thoughts?

Thx

The perfs look fake to me. Scammers will try any trick to make people believe in their work, blind perfs is one option.

punched holes and unpunched holes look too round

Suspect to my eye too.
Don

Thanks, very helpful

I'm guessing this is due to differences in how stamps are authentically perforated vs. how the perforations are counterfeited. Why is it that authentic perfs are not well-formed circles?

RK1468: Early U.S. perforations were done by perforator perforating wheels so that the movement of the paper through the wheels gave it oval looking holes in the direction of paper movement. This is different than using a stroke perforator that punches straight down and through a non-moving piece of paper giving it round holes which is what perforation fakers usually use. An interesting book on this is "How To detect Damaged, Altered, and Repaired Stamps" by Paul W. Schmid.

Thanks, Jogil. I knew that nice and tidy round holes were often seen as evidence of counterfeiting but not the rationale. I have seen the book you mention referenced before and may need to review it. Thanks for the input!