There are two A N Jacksons in this site. Mine, in the library, has raised carving with motifs suggestive of yours. A good shot of the signature shows on my Jackson. Nord says he was in West Virginia, probably from PA, and the box on his is very much different than ours, which have similar side plate outlines. I just searched for “Jackson” on the site here. Yours makes the 3rd A N Jackson I know of.
Bill Paton