Just to be clear, I'm totally on the fence about this. I believe it could easily have been a factory installed item, yet still never an official option. Totally agree that with the '66 model year they were experimenting with just about everything and made running changes, but that the pony interiors could have had any number of normal, or strange and bizarre reasons for having been installed at the factory.
Even perhaps a special promotion group that never made it to the '64 World's Fair on some car and someone decided to use it up on the Broncos!
Maybe it was simply the late-66 built transitions between the '66 and 67 model years? Could be they were missing something between the transition from Silver to Parchment and someone said "hey, we got there here funny looking material that nobody's ordering for the Mustangs" or "we were going to put it on the Falcons, but decided to stop making them..". That might explain why some registered '67's had it too.
By the same token, it's not out of the question that it could have easily been dealer installed. Especially by one or at most a very few dealers who were trying to make a statement. The material could literally have been ordered in bulk, or in premade covers for the front and bulk material for the rears.
I'm with those that think we should try to get the origins and build dates of as many Pony Broncos as we can. It would be extremely interesting to find out if they were built in the same time frame, or separated throughout the year.
Here are some pics of the one I had. Like I said, as far as I could tell, they are the only covers that were ever on the seat. So if the PO theory is true, they would have had to find a new seat frame, foam, and the wood backing. Doesn't seem likely. Plus the one BajaFresh75 had was all the evidence I needed.
I'm curious what you see JG? What about them says they're original? And what does that decal with some shipping info on it say?
...I really had my doubts several years ago, but the past several years I have seen the interiors from all over the country, even one '66 that was beyond bringing back....had been sitting in a field for years and years,(in the midwest) and it had the "pony" interior...
Seeing the same interiors all over the country on the '66 and '67 tells me plainly that "Pony Interiors" were a factory option!...
I'm curious about this too fordfan. Why does their spread out nature have anything to do with the factory? If they were dealer installed, wouldn't they be all over the country too? Even if it was just from one dealer, they could still be delivered all over the country. My '71 was as original as they get and the first owner was in Montana. But in just over two years it was registered in CA. Even if only one dealer in the US was installing something, vehicles could easily end up all over the country in a very short time. Change that to multiple dealers, and all bets are off.
So again, I'm not against it being a factory installed item. In fact, I lean more that way than the other, but I don't see the fact that they're all over being proof of it.
Paul