"The one thing I'm looking for is the grey [or tan] plastic cap for the drivers seat that sits at the joint between the back and the seat that holds the seatbelt and hides the joint and spring."
1984-87 COVER, passenger seat back reclining hinge, lower
20596788 $8.51
1984-87 COVER, driver seat bac reclining hinge, lower
20596789 $8.51
You have to paint these to match, so you might want to look in a junk yard.
From: Scott Backer
Installation is the reverse, you might have to push and shove the seat back onto the studs, but it will fit.
From: Jason Wenglikowski