[Autoban]

I used to work for VDO in the City of Dortmund were these oil pressure senders were manufactured. I also used to be the Supervisor for the department that manufactured these senders (from about 1982 through 1987).
All 10 bar sender units use the same diaphragm and as far as I remember the same wire wound resistor. Actually, as far as I remember, all of the sender units used the same resistor except maybe some very special units. The numbers 3.79 and 4.82 represent the month and year of manufacture (March 1979 and April 1982). The numbers 29/10 and 29/50 identify type and model of the sender unit. Any sender starting with 29 is a single output sender to be hooked up to an oil pressure gauge. If the number starts with a 30 then it was a two output sender with one output for the oil pressure gauge and one for the low pressure warning light. The numbers after the / (like /10 and /50) most of the time represented the size of the threads connecting the sender to the engine, but could also mean different surface plating on the sensor. I remember we manufactured one for Harley Davidson with a chrome housing on it.
I am surprised you are using a 10 bar sender unit. My '86 Carrera has only a 5 bar scale on the gauge and I thought all Porsche 911 engines are 5 bar engines. If you hook up a 10 bar sensor to a 5 bar engine you will get inaccurate (too low) pressure reading.

All of this is from memory from 30 years ago.

Juergen