Adding factory AC to a 1967 and having it be correct looking is a huge task. Trim tags are easy to replace, but this one looks good and numbers align. The fact it looks so correct and is not on the tag gives me great pause.
For AC, the firewall had to be replaced or hacked up under the suitcase. This is also in the area of the hidden VINs so if replaced there would be no VIN or wrong VIN. The dash also had to be replaced with an AC dash or have the round vents and center vents cut into it. No easy way to install those round vents in the curved sheet metal, so if cut in, it will look like it.
Were you able to see both hidden VINs? The top of the firewall where the hidden VIN is also has AC components near there.
Any pictures of the hidden VIN?