I have a 657-2 that I bought and don't really carry, so I'm considering selling it. It's a full lug 6.5" barrel, unfluted cylinder, square butt model. The serial number prefix is HTR and the number portion is under 150. I don't have the box. It's factory original and in very good shape. Values I find are several years old, and I'm having a hard time ascertaining its worth. Can anyone offer any help? Thanks in advance. And I can post pics tonight if that will help.