I'm new to this forum so please forgive me if I'm not doing this post correctly. I have a Smith & Wesson 22 revolver that I'm trying to get more info on. I have the the Standard edition Smith &Wesson catalog 4th edition. I'm having trouble finding info I need in it. My serial number starts K6363XX. It Says 22 long rifle CTG on the barrel. The serial number is on the frame under the cylinder. It also says MOD 18-. Theres also a 5 by itself on the inside. Any help is appreciated.