I completly agree with Lynn, and Vern. This fake stuff is really ruining the hobby.
This is not buyer beware anymore - that is fraud.
I had a similar discussion about repro POP's on Team Camaro, some of those guys just didn't get it.
Fake POP discussion Interesting reading - I have a way with words.
If it were me, I would find a tag off another 1967 Car and put that up there in it's place.
Most people wouldn't know the difference, and the ones that do, would understand your explanation.
Otherwise, I guarentee somewhere down the road, someone is going to get burned. Maybe your great-grandson will sell the car. He will believe it to be a real tag. It never fails.
I have a large collection of trim tags (for refrence only)
I would be glad to find you a Cadillac tag or something.