Hi Dallas! The washer is actually seam sealer that goes between the washer on the bolt and the body! See picture!
Tonight I disassembled the front seat! It was funny because I could notbelieve that it was so many codes, stamps etc!
Backseat has it's own partnumber and date code tag. Built January 4,1965 and the seatspring are madein December 7, 1964. The seat foam was ink stamped with Chrysler Corporation and the partnumber.
The fabrics are stamped with TEX and 11 64. I'm not sure what TEX stands for but 11 64 stands for November 1964.
Now the seat springs are ready for some serious glass beading and a shot of black paint.