My passenger-side rear trunk hinge broke free and it looks like the strap had broken many years ago.
The part number is 91451221510 and it is part #6 here:
http://www.pelicanparts.com/914/Parts/Body/rear_trunk_hinge_big.htm
It's the strap at the bottom of the hinge that limits the travel and prevents the hinge from bashing the small deck-lid grills.