Tim,
I didn't see these labels on my 69 GTV (but that doesn't mean they weren't there when it left the factory). But I've never seen any photos yet showing these labels. Also, you might want to post this question in the Spider or GTV forums (I never saw this post before today) and I'm guessing that many guys probably haven't subscribed to this forum. That said, I wonder who else may still have these on their boosters?