Accel. pedal fell off

[dhowitt@iddis.com]

This should be an easy one.  Car is 1989 100Q.  The accelerator pedal fell off. 
 Just the plastic top pad that pivots and faces your shoe.  Underneath is the 
real mechanism with spring attached and that is fine, I just step on that 
directly.  But it's not clear how to reattach the top piece.  No provision for 
screw, clip, or etc. is evident.  It just wedges into place and works fine for 
a little while then falls off again.  I checked bentley manual but no detail on 
this.  Any ideas appreciated.  

Doran Howitt
IDD Information Services
Livingston NJ USA
dhowitt@iddis.com