That the same one you texted me pics of? That one was etched mk3 on the starboard bow so I'd guess 3rd production run circa 1995. Give Lew Horton a call or email, they'll have better info. I've heard tell LH kept better records on these PC guns than S&W did
PS: Curses, you got me thinking about what to do with my M66 and M19-2 snubbies
Cheers
Bill