My Jan Metuchen coupe also had the wider gold bag when I obtained the car. Its certainly an original bag but wasn't sure if it was original to that car or not. At the time i thought that bag wasn't being used until mid year so I went with the smaller white bag. Im curious now what the majority is if i have the wrong bag installed..
Remember that there was the smaller/narrower bag that was often in the kits to add windshield washers (not a standard item at the time) by the dealers This can add confusion when comparing what we find years later.
Real hard for me to offer allot of info since there are few good unrestored NJ 65's out there.
Only example with a bag still in it is the screw on style I found in 5T07T1618xx which had a projected build date of 10S. Car is report to have had 49K miles. Bag printing is pretty nice and white thought the brass grommets are old and tarnished