Several years ago I was looking for a replacment for the first bronco I sold. Found an original '66 half cab with a bench set that had everything. Low mileage, but rust. It was extreamly complete. Horn ring, hub caps, not a part was missing or beat up. It was also the 2nd ever sold by the local dealer.
I passed on it. I wanted a toy. Something that I could play with without destroying. That truck had too much history behind it and was in need of a restoration to stock. Not what I wanted, which was a hot rodded, mildly tricked truck.
As for the rarest vehicle? It is the survivers. Original unmolested vehicles. They can only be original once. Anybody can restore one or hack one up. It takes a lot to find an original and keep it that way.
I can open the auto trader and find a dozen toys/beaters anyweekend. I can search aa little harder and find people restoring them like new. But the used and not abused, survivers are becoming more and more rare everyday. That is because you can't build a survivor, it must be one. They get rarer everytime someone gets one without realizing what it is, then goes out and starts putting a lift on it and reworking the engine. Thn they want fresh paing and custom seats. Poof, another survivor gone forever.
This isn't just a Bronco thing. All cars are suffering it. I looked for a model T a while back. I thought it might be a fun toy. Drive to work on nice days (only a few miles now), run to the local store. Went shopping. All I could find were T-bucket hot rods, restored cars, and bucket-o-parts cars. I found 1 survivor out of 150 cars I was looking at in 1 day.