Well, friend, I'm guessing you overlooked my question about your old Smith's trigger . I was also curious about it's date of make.
No, I saw it, just didn't know how to answer... then I forgot about it.
I still don't know how to answer. As smooth as a vintage S&W? No stacking. None. And I love that in a trigger - it's why no DA autoloader's trigger has ever done it for me. I would estimate that the weight is the same as any K-frame - like your M&P - but the wider target trigger on the 19s makes it feel less, to me anyway. I bought it used, so no telling if the previous owner installed lighter springs.
Since we are talking about a 19, it is worth mentioning that the forcing cone and top strap are both in perfect condition.
I have no idea on the date. Does anyone have a SCSW that I could give the SN to?