I'm trying to help my husband find the value of this gun. We can't find it in any books or online. Anyone know where to find it or what the value might be? It's a Smith and Wesson 1911 .45 caliber with 5" barrel. It's a Horton Special Edition that's engraved. Called S & W and they said it's a model 645. Horton said they were made in 2000 and 500 were made. Thanks!