I don't have any problem accepting this as a genuine. But it can be hard to ID them from just a
monogram if it's not one of the common ones or there's nothing distinctive to a particular
mint.
You said you searched through
PELLA thoroughly. So you may have tried this already, but did you see the
Symbols page with "Constituent Letters"
search?
https://numismatics.org/pella/symbolsIt looks like there's a "K" on the right, so I limited it to "K" symbols/monograms and
still couldn't find it -- they can be tricky, though, maybe it's a sideways V or

. (Trying "K," the closest I noticed was a much later
Smyrna issue, but you may see something I didn't.)
https://numismatics.org/pella/symbols?symbol=%CE%9AThere are so many minor variations, though, that many are unpublished. Your best bet may be to keep an eye out for a similar symbol and try to compare
style to decide if it could be from the same
mint.