Help identifying/confirm age/area of antique desk

Looking for any help in identifying/confirming the age and value of this desk. This is what I know.

Early narrow dovetails (hand made). Hand chamfered bottoms on drawers.
Solid Walnut. Mostly 3/4" , Backsplash and back are about 3/8" to 1/2" thick. Angled surface and right surface are leather covered. Angled top lifts for storage. Legs appear to be bell and baluster type.

Was told by prior owner who bought at auction (years ago) that it was made in Kennebunkport Maine area. My furniture knowledge tells me its least 150 years old but is it possible that it is 18th century? Not that familiar with this leg style but research says it was popular in 1700s America.