S&W revolvers do not have a transfer bar. They have a hammer block, which serves the same purpose. They have had this feature since sometime around WWII (don't know exactly but I am sure someone here will). The M13 was not introduced until the mid-70's, so it is safe to say that all M13's left the factroy with the hammer block.
To my knowledge NYPD always issued revolvers chambered for .38 special, not .357 magnum, so M13's going to them would be a bit unusual. NYSP (New York State Police) did issue M13's from the mid 70's into the early 80's when they switched to N frame M28's, but I have no info on any recalls of these guns.