You can get them free at the Smith and Wesson sponsored ICORE matches. Well, maybe there is the match fee. My M66 cost $160 match fee and I didn't even place.
It WILL find a new home. Let's hope that it's with you. I have a Model 66 4" like what you have described and it is a great gun. Here it is along with it's 2 1/2" brother.