72 Dart Swinger Front Seat Parts?

The 72 Swinger I have is missing some front bench seat parts. When looking at the seat where it pivots closest to door sill, there is a curved bar that attaches to a shaft that folds the seat down to enter the back. Every time I fold the seat it comes off the shaft and then the seat comes out of the hole near the arm rest. I have this problem on both sides so don't know what I'm missing. Any pics or info on parts I need would help.
Thanks,