This is a bit out of scope but has a little relevance. In another lifetime I owned a 1969 Dodge Charger Daytona 440 auto car. One of 503. While working on researching the car I found the broadcast sheet up under the dash on top of the glove box, and the second broadcast sheet under the rear bench seat. Then found a third broadcast sheet for a DIFFERENT DAYTONA on the Back of the rear seat.

When Daytonas were created from Stock Chargers, the outsourced company subcontracted to do the conversions( in their haste ) ripped all Black interior components and threw them in one pile (literally) ,same with white interriors and so on. What ever daytonas were being worked on at the time, the interriors went into the pile.

As cars were completed and sent back to chrysler, the interriors didnt always match the car it had come down the assembly line with. 

 I posted my find on the NASCAR Daytona / Superbird club and offered to reunite the owner with his broadcast sheet with proof of ownership. I received pictures of a fender tag and the car itself and finally sent the 3rd mystery broadcast sheet to its owner in CT. Happy ending.

Your sheet could have been a snafu on the assembly line similar to what was mentioned above, could have had a replaced seat somwhere along the way in its 50 something year life...who knows.