I would guess it was closer to mid Oct possibly into Nov 65, looking at other cars with similar Shelby VINs, but we'll not know or even be close without more data points to compare to. Of course the carbs were built in batches so some cars would have receive "recently" made carbs or much older stock depending on other factors and the luck of the draw. Sounds like your not really focused on dates and you have something that will work. As far as jets in the carb there is no way of knowing if the ones in yours have been changed so time to pull it down and check to see what the little number on the side tell you and go from there.

