Any shots of the tang and the top of the comb? Looks like it is definitely a long tang - would love to see the shape. The length of it would lead one to suspect North Carolina or Tennessee.
Is that a diamond shaped silver inlay on the comb?
The patchbox is very "Sheetz/Sheets" in form - almost like it was cut from one of their patterns. But the engraving is more naive. maybe someone who apprenticed with the Sheets.
The sort of squashed-looking star on the cheekpiece is reminiscent of some North Carolina guns, but overall I'd agree its from Virginia - the keys with escutcheons only on the rear one, wriggle engraving on the escutcheon, the triggers (I really love the triggers on this gun) etc. The use of round thimbles in paring with a full octagonal barrel is atypical for the major riflemaking centers in the Valley, but something you would not be surprised to see on an Applachian region gun, from Southwestern Virginia or Tennessee, maybe over to Cumberland plateau.
Whisker does not list any Hoffmans in his "Virginia" books. Jerry Noble lists a Charles Hofman in Shelby County Tennessee in the 1850 census, and a Louis Hoffman who worked late, in St. Louis and later Vicksburg MS.
Other possibilities on the name? There are Huffmans known in Virgnia, and Hollan/Hollands in North Carolina and Tennessee.
So overall to me it sort of has the feel of a Virginia Valley trained smith who moved west/southwest. The sideplate may be a replacement - real unusual form. So most likley Virginia, or points west...
Guy
