I have that book. Wilson covers much more in terms of revolvers and lever guns, but he does touch on some doublegun broad points. All the same, neither he, nor Hutchins (lovely book, but his chapter on engravers has some glaring, simple errors) assert that Loy did work for Smith, be it in Syracuse or Fulton.
So...just so Im clear, no one on the LCSCA forum has actually seen a Loy engraved Smith, right?
I feel like because Loy's work is usually identified unsigned, he is perhaps the most over-attributed American engraver.