hello, i just inhereted 3 s@w revolvers.I am trying to find out about them. one of them is a 38 cal. fixed sight 4in. with the firing pin on the hammer 4 screws on sideplate,1in front of triggerguard,old fashioned blade front sight,serial#c 273xxx.Is this a M@P? The other 2 are identical 22cal. adjustable sights recessed rim cyl.6in. 4 screws on sideplate1in front of triggerguard,integral firing pin,finely tuned action.serial#655xxx and 674xxx.Any info would be greatly appreciated.thanks