Joe,
I suggest you contact SMS in Canby, Ore. Over 30-35 years I've made a number of purchases from SMS. Including some pretty old ('42) original seating material and some pretty unusual original material from the 50's also. They have literally 1000's of bolts of original material. The owner's name is Doug Pollock. Good Guy. Incidentally, they'll send a FREE sample.
A link to their homepage, with phone number follows. I can highly recommend them......
SMS Link Good luck,
Bill.