I don't have the big book in front of me, but I can tell you that my 19-3 is a 1973 revolver, so it's safe to assume that the one you are looking at is somewhere near that date. I've got a 19-4 that's a 1978/79 gun.
Attention Brass rats and other reloaders: I really need .327 Federal Magnum brass, no lot size too small. Tell me what caliber you need and I'll see what I have to swap. PM me and we'll discuss.