Sediment traps

[quk@sievers.com (Phil Payne)]

The works and parts fiches for the ur-quattro (MB) show a sediment trap (which  
Audi calls a fuel filter, just to confuse the unwary) in the line from the tank 
to the _REAL_ fuel filter.

As part of my fuel system overhaul, I planned to replace mine and ordered (I 
have it in my hand) a replacement 811 201 511D.  But on lifting the car - no 
sediment trap.
 
There has obviously been one - the mounting lug is present, albeit amateurishly 
bent up against the floorpan.  It is now bypassed by a single line going from 
the tank to the fuel filter.
 
Questions:  
 
a) Anyone got a car with a sediment trap, at 140k miles, ca. 1988?
   What's in it - does it do something useful?
 
b) Has anyone seen a TSB saying: "Get rid of the trap?"
 
c) Any other questions you might think of answering without me taking the 
   trouble to think them up?  (I know this list!)

--
 Phil Payne
 phil@sievers.com
 Committee Member, UK Audi [ur-]quattro Owners Club