Welcome from Virginia
Welcome to the Forum from Virginia!
You have what I believe is known as a "floating J" serial number which as already posted was only used 1971 to 1972 by S & W.
Also from the frame stamp "Mod 36" I would say you have a Model 36 "no dash".
Mine pictured below is a January 1967 ship date and has the original box and documents. I have an insurance value of $600 on this gun and box, and that is about the going rate around here IF you see one for sale.
If the box you have is THE ORIGINAL (with matching end label) and documents then I would say you are in the ballpark at $600 for a private sale. Repop boxes and end labels abound on flea-bay and add absolutely nothing to any knowledgeable buyers.
Gun only in good to very good condition is right around $500 for the last private sale I saw in this area but indeed, that was 2 years ago, pre-pandemic, and when private sales were still allowed between individuals without having to visit an FFL and pay $25 - $35 transfer fee.