Hi again..take a look at the home page database .Click on the picture in the top left corner, that will take you to the home page. Then, click on the database button. Scroll down thru the engine number entries, and you shoudl find your answer there. Unfortunately we do not have a large amount of original engined 3A's in the database around your numbers but you can get a rough idea of its production by tossing the obvious oddballs in the list. Ignore those with engine numbers that are obviously from something else, like the ones that begin MC, 4T , etc...There are also several that do not fit the pattern, because they are 3A engines from other 3A jeeps that were transplanted at some time in the past.
I took a rough look and it seems you are pretty good with your year but like I said it was a real fast look. You might want to PM Bob W and see if he �has better data point to rely on in his data for his research. He has a lot more info than we do here about numbers..