split bench seat locking washer?

Im having an issue , My 72 Split Bench seats are missing the washer that locks the top back of the seat to the bottom metal peg. The seat backs fall off the peg and I noticed it might be dangerous if i was driving and the back slipped off peg. The washer locks would be under the plastic side hinge covers. Where could i get a set of these locking washers . Any help Thanks Eric
Author: SgtLee511