They were made by Hogue - they are X-Frame Big Butt grips. I tried to find them on Hogue's site, but I can't find anything for S&W revolvers anymore. They do make them for Dan Wessons. Here is an example . . . .Are those k frame wood target grips?
http://www.hogueinc.com/store/produ...ood-top-finger-groove-big-butt-checkered/3025