Bob,
Those are the TALO grips and it's a factory option. My 642-2 came with them. I may still have them somewhere.

That's right. Mine came with it too. One thing with j-frames is you might end up with a small collection of grips. Some are less good looking but very functional like uncle Mike's boot grips. I have from Barami to classic S&W grips with Tyler extension. Every time I am bored with the look of mine I go ahead and change grips. But when I carry I pretty much stick with the Uncle Mikes.