Smith & Wesson Revolver K, L & N Frame All Models Made Before 1988 Includes All Pre-Models Blue Steel Side Plate Screw Set Part# Z1
Replace those boogered up side plate screws while they are available!
Include 1 flat head screw (goes under the pistol grip)
2 Crown screws for the other two holes the one used for the Yoke retention/end shake may require fitting so the cylinder opens & closes easy. These are Factory S&W new old stock.
How to determine the model number of your Smith & Wesson Revolver. Swing out the cylinder, check behind the yoke on the frame for a MODEL NUMBER.
Gunsmiths Required: Disassembly and Assembly required to replace part
Some parts may require installation and fitting by a qualified gunsmith Factory replacement parts are manufactured to the exact same specifications and tolerances and use the same manufacturing materials as the original parts