I read that in the past Smith & Wesson 3rd gen had a recall concerning the grips. The new grips can be identified by a dimple on the bottom of the grip, next to the large opening.
For more details please check:
Firearm Recalls and Safety Warnings- FirearmsID.com
I'm not sure how this dimple looks like and appreciate if someone could upload a picture of it.
I added a picture of my 3914 grips, do I need to replace it?
Thanks