68- early 70 12 bolt fill plugs.
 

Found 2 of these .
One in box and one without.
Right stuff?
The dimple??

Pics 2- 3 are 68 [left] and 67- older [right] type side by side

Thought there was a hub bub about this here?
Maybe the Chevelle site?

Anyways the one in box has most of the dimple removed like the used example.

Lack of the 'W" is the glaring issue to me.

The new ones are definitely service parts.