1c Franklin. Trimed?

Hi dear stamp collectors and philatelic enthusiasts.
Wanted to ask for opinion on this one?
Trimed?

No one is trimming a #23 to create a #9.
https://stampsmarter.org/

Yep, that's correct. It typically goes the other way around.
#9's get perforated fraudulently to create fake #23's, since they are more valuable.

I haven't seen many of these, actually. LOTS of other stamps with added fake perfs though.

Well, there are more out there than people think...maybe not a ton, but more than is obvious.

Once I got pretty good at 1c Plate 1L colors and their progressions over time, years ago, I started noticing #23's with early colors (1852). That was a major red flag. I don't know if its enough to call a given stamp out as bad, but its strong circumstantial evidence to me -- and I saw enough of these, to where "they are out there".

Overall, I mostly agree, that it hasn't seemed to be a huge problem off-hand.

I suspect that creating decent perf 15 is more difficult then the larger ones. Far fewer uses obviously.