My grandfather-in-law has this old, six shot .32 Smith & Wesson revolver that has his dad got from a family friend MANY years ago. There are several dates printed on the cylinder but nothing indicating a model number or manufactured date. The gun has a 5 digit serial number beginning with 15___. I was hoping that with the pictures below, a wheelgun aficionado here on the forums might be able to ID this gun so we might be able to figure out some of the history. Thanks in advance for any clues!