Vintage G&S but did I have to mention vintage lol!

So by now you’ve probably seen that I heard old boards! Thing is most of these were birthed before I was! Case in point I turn to you guys who are far more knowledgeable in these matters. What I dug up this week in a G&S(custom) sting model after the legendary aipa design. Now all the info I have to go on with this one is the number 3959 and what appears to be 68 which I’m guessing is the length or G&S! It’s anyone’s game at this point. All I can get from the locals is early to mid 70’s! Who can do me one better and give me some real info!