Not sure that I am grip expert, but I have a collection of S&W grips, Colt grips, and some others. I also have a box full of pachmayrs and I've owned dozens of other grips, which I sell on ebay from time to time. Its like a "cottage collection" within my gun collection. I started of just buying loose sets at shows in case I ever needed them, then I started looking for specific types. I often will buy groups of grips, 5 or 10 at a time, and sell the ones I don't want.
If they are S&W K frame, they are very common. Perhaps the exact style is not, or perhaps the maker is not BUT K frame S&Ws are very common, and thus are their aftermarket grips. The plastic today is probably actually better, but other stuff from back then is a better quality. I would say they are probably worth about $20. After market special material grips (stag, pearl, ivory, etc) are often worth bigger money. Also factory grips can be pretty valuable, as can aftermarket wood grips such as Kearsage or Roper's.
Winchester 73, the TFL user that won the west