89 Quattro 100 oil pressure warning

[David Boyd]

89 Quattro sedan 200K+ KM

The oil warning lamp in the multi function display came on a few days ago
and the oil pressure gauge went to zero, just following some scheduled
maintenance (including an oil change) by my regular mechanic.  I returned
the car to him immediately -- only two blocks from his garage -- and we
diagnosed the following:
1) Some coolant had leaked from the upper hose onto the oil gauge wiring
2) Oil sump full, pressure tested to 30 PSI at idle and at 3000 RPM
He cleaned the terminals on one of the sending units but now the gauge reads
just under 1.2 bar all the time and the warning light comes on
intermittently.  I have a number of electrical demons in the car which
effect the back up lights, and some other items, but have not been able to
identify where the short may occur

Questions:
Is the car safe to drive with this oil pressure?
Could it be a ruptured oil filter?
Should I replace the sending unit(s) or is it another electrical fault
Any suggestions as to what to what my next step should be .. I want to
correct the problem but can't afford to spend too much time investigating
the cause if it isn't critical to the operation of the vehicle.

Thanks for any advice you can give me.

Dave Boyd
daboyd at kingston.net