Looking at several original flip top assemblies I have and I notice two variations. One style has the metal tab screwed in place to pop the lid open. The other style has no provisions for the tab and instead uses a rubber grommet to pop the lid open. My originals have one type or the other. My assumption is that if you had the metal tab you wouldn’t have the rubber grommet. I’ve seen pics of restored cars with both the tab and rubber grommet but don’t know if those just got added during restoration.

It is my understanding that all Challengers optioned for the flip top cap also came with the locking gas cap. The locking cap does mate up well with the rubber grommet causing the flip top lid to pop open.

Anyone know if this was a design change, early vs. late thing?

ALSO... any recommendations on how to remove and replace a chrome flip top lid? I’m not sure what to call that pressed in pin, or how to get it out without damage to the lid.