Eric, here is one engraving of a signed LeFever that was done by Jacob Glahn. After his name is the letters SC meaning sculptor as this was a common thing for engravers to put after their name. From what I have read, Jacob and his three sons, George, Theodore and Gus went to Fulton after the closing of the L.C. Smith Gun Co. in Syracuse, N.Y. in 1889. If in this obituary of Jacob, saying he and his sons came to Fulton in 1893 would then explain the existence of the Spangler brothers who also engraved for L.C. Smith Gun Com. It is said they only engraved at Hunter Arms for a few years. Jacob died in 1902. Theodore went on to Colt and engraved a Colt revolver for then President Teddy Roosevelt. Jacob's brother Wilbur also went to Colt and became their top engraver. There is more information about Wilbur than the rest.
Very few guns were signed by engravers and you just have to look and study the different ones. In my opinion Jacob's dogs had a blocky head, English Setters do but his looked very blocky. I believe this is a Jacob Glahn engraving.