The Standard Catalog of S&W isn't too helpful. It lists the models 32 & 33 starting post war production in 1949 with #54479 and ending with #122678 in 1969. Fortunately, you provided excellent photos of the box that offers several clues. Your 38 RP is a dash 1 J frame. The J frames started in 1961 when they stopped production of the I frame so that give us a starting date. The lid of the box lacks the inscription "A Bangor Punta Company" in the lower right corner. BP bought S&W in 1965 and the new logo boxes started appearing the next year. So we have a most likely end date of 1966 or so for you revolver. The flat latch cylinder release was replaced by the new style that's on your revolver about 1966. So all the clues point to 1966 production. But the model 33 was a slow mover and could have sat in inventory for much longer before being sold by S&W.
Very nice model 33! I wish I had one this good in my collection.
