DiamondJim: Thank you for that - I have resumed, and again terminated, my search through my 430+ page long LARGE Smith & Wesson reference book without finding the answer I (we) are looking for - this is not the first time I have been unable to ascertain a manufacturing date from this "book" via serial number - even while holding an older S&W revolver in my hand and looking directly at the serial number on said revolver!?
Looking at your excellent picture there is NO doubt that you were/are correct in relaying that info about the "J's" placement.
I'll keep looking but I see NO similarities in your serial number and any classification of serial number manufacturing dates showing in my "reference book"!


Wildhobbybobby: On page 209 of my "reference book" in the portion of the "reference book" dedicated to the Smith & Wesson Model 36's there is a chronological chart by year indicating "engineering and production changes" for the Model 36 that I will quote:

"36-1 (1967): Indicates 3" heavy barrel."

SO... maybe that was the first year of the 3" heavy barrel's or the only year of the heavy barrels - I can't ascertain?

More later (maybe?).
Hold into the wind
VarmintGuy