It?s a GTA has the dual screen and the nipple,I have read the other posts and didn?t have a clear answer,
Look through pictures of other 67 S codes and on unrestored/original examples I see no evidence that they every received a cubic inch decal on the lid. No glue or wear patterns either. At least one of these examples is shown in the unrestored picture section of this site. Not the only Mustang this apparently happened on - just can't explain why.
As far as the reproduction likely IMHO something that Jim O started to fill a void and a want/need so he may have made something up to sell and their use continues to this day. He did a number of other incorrect for the application that also continue to this day. You will see them on cars around the internet and at shows
Here are just some of the examples I rounded up. Please ignore the owner/company added sticker and added breathing holes in a couple of them
Only have one example from a unrestored car I had back in the 80's but it came with a T Bird blue sticker on it.
As a side not I've got a handful (maybe a half dozen) Thermactor GT's with the snorkel style air cleaners but that is another subject. Maybe a supply thing - don't see a pattern yet