Hello,
I have thought about ariels and Oliver Pinchots opinion that the dagger could be made in Daghestan or Tiflis. I found this map in the internet (see also the link) and if the dagger has been made at the early 19th century these areas were a part of Persia at this time.
https://de.wikipedia.org/wiki/Kadsch...an_1900-en.png
In this case it is not wrong to say "it's (northwest) persian", but it is also right to say "it's from Tiflis or Daghestan"
That would explain the persian decor and the similarity of the blade to georgian examples. Maybe the decor was made by another artist than the blade.
But I think the customer was a Persian who maybe lived more in the south.