Accelerator Pedal - 89 100

[Dave Conner <conner@cfm.ohio-state.edu>]

Why has the accelerator pedal cover fallen off on my 89 100?
It appears that it should snap back into place, but it won't stay.
The design of this pedal is quite different from the earlier cars, 87 5k
for example.
The newer type pedal is a hinged affair with a spring under the cover which
the foot rests on.

My guess is either something broke or else I've lost a piece, but I can't
see anything obvious.

This may sound trivial but it's definitely annoying.  
Bentley is no help at all.

Dave C.