Update: Today my NOS #4002 headlamps came in. Let's take a look.

Bingo!


Date code: October 1969?


Below the packaging to look for:





Below, the second #4002 bulb I got was dated June 1963. It's the same bulb and packaging.



Another thing to note. The later #4000 GE headlamps have DOT in the ink stamp and the class lens. While the early #4002 bulbs have SAE in the ink stamp only: