Condolences in the loss of your father, but welcome to the S&W Forum. With sufficient information we should be able to identify it. First, make sure you give the complete serial number from the butt, with any letters if present. Also, if you count the number of chambers in the cylinder… 5=J frame, while 6==K frame probably or maybe an N frame (less likely.) Also, counting the screws on the sideplate can be helpful. Remember, there may be one hidden behind the top of the grip. Really, if there is one at the top beside the hammer there are four there. Also, look for a screw in the front of the frame just above where the trigger guard ends. Collectors identify them as 3, 4, or 5 screw variants, helping with dating.
Froggie