Big $$ ABS problem

["Theodore R. Harlan" <trharlan@one.net>]

Car is a '90 CQ, #695-- pretty early build date. I need serious help.
I have the infamous pedal BOING when coming to a stop with the ABS on.
My inspection leads me to believe that the problem is the right front
ABS sensor. The Left front gives me an increasing reading on the AC
voltmeter (crude, but I have no Oscilloscope) as the wheel turns faster,
the right front gives me nothing-- regardless of spacing from the axle..

The kicker here is that it seems that the wheel speed sensor is
different than the one that shows up in everyone's book. The one in the
book is $15 or $30. The one that I seem to need is $200-$300.
Furthermore, as far as I can tell, my sensors have a much larger
diameter, that's why the spacer caps that the fiche shows don't even
come close to matching my hubs. According to parts places, the # I give
them is for a N/A 200Q.
The number on the sensors: AUDI 893 927 803   WABCO 441 032 639 0
Now, if the little sensor (the one everyone's fiche says I need) and the
big sensor work the same, I could have a big sleeve machined and put
this thing to rest. If they work differently, I'm probably pretty
screwed!
I need help badly. If anyone knows anything, or has a good dealership
that can research this, please let me know.

Ted Harlan