Upto chassis 1J Y 300000 the compressor fitted should be made by Sandem (SD 7 V16).
Part number listed - 1J0 820 805. This is also fitted to the 4 cylinder engines, but 4 cylinder engines also have a option of a zexel compressor which will not fit V6.
Chassis 1J Y 300001 onwards has the Sandem ( SD 7 V16 ) but has part number 1J0 820 803 K, this is also fitted to the 4 cylinder cars.
Hope this helps? basically as long as it is made by sandem and has the same connector it should fit?.
Jochen.