Original part number 928 126 010 01. Bosch - is the original manufacturer of the 928 AC Compressor. Fitted from 1978 to 1979 to all 928 Worldwide. Bosch 0140 903 50 is the manufactures part number. These are re-built units. A Core is required. There is a $350 Core Charge.
The compressor comes filled with Mineral Oil which is compatible with R12. If you have converted your AC system to R134a, drain the compressor into a can to record the quantity used. Replace with Ester Oil as it is compatible with Mineral Oil and R134a.