CHeck with the maker of the grip.
GunBroker.com
Take it to a gunsmith
Need a sn to date it.
250-500
With no other information supplied, 100-500.
69-70
One has been.
Good condition with orig grips blue $1000 nickel $1400.
Wood
Depending on the exterior condition with pearls, $700.00 to $900.00.
On the bottom of the grip. It is sometimes covered up by the wood of the grips. Take them off.
Smith and Wesson Model No. 2