if it has the correct grips, and a 4in barrel is a + i would think around 600.00 but gunbroker is a good place to look to get an idea. you can also sell on it gb the person you sell to needs to have a ffl license or a c&r license will be ok because the gun is over 50 years old, but they must send a copy of the license to you and you can only ship to the license address.
post photos for a more accurate estimate.