'92 100S - dead fuel gauge?

[Nitz Karl-GKN001]

I'm looking for input on a problem I'm having with my fuel gauge.  It
started going flaky last Spring (intermittently reading a level, then none,
then only when almost full, then not at all).  I decided to dive into the
tank and check the fuel level sender last night.  The "wipe switch" clearly
showed different resistances at different "levels" by measuring at the
contact pins at the top of the sender.  Also, the one wire (VIO/BLK)
measured continuity back to pin 3 of the red connector on the back of the
instrument cluster.  The other wire measured a direct connection to ground.

Has anyone had their fuel gauge go bad on this type of car.  I have 111k
miles on mine now.  Is there a problem with the IC circuit board I should be
looking at.  Do I need to think about putting some Stabilant-22 on the
connector pins?  Is there a procedure for testing the fuel gauge once it's
removed?

Thanks for the help,
Karl in Johnsburg

'92 Audi 100S, 111k miles, never a full tank :)
'97 Chrysler Sebring LXi, 61k miles, wife's "German" car
'84 VW Jetta Diesel, 184k miles, needs cyl. head
'85 Honda VF500F and '84 Honda VF1100S