In the 60's Chrysler contracted with various 'custom houses' to do modifications to their cars when small batches did not justify production line work. Examples are the Superbird/Daytona and the Hemi Darts and Barracudas.
The workers would usually remove the seats and toss them in a big pile while the mods were being done. When it came time to reassemble the cars, they just grabbed a black seat for a black interior car, etc. without worrying about which actual car it came from. But, on these cars the broadcast sheet - the paper that specified which options the car had - was usually placed in the springs of the back seat.
So now it is common to find an all-original car with the wrong broadcast sheet - this is accepted and does not hurt the value of the car in the collector world provided the other numbers match up.
