It IS possible Stuart but its a trial and error job with a timing light - you will need a lot of patience. Get a good bright torch and you will see the scarring on the end of the cam where the spiggot broke off - try and line this up as best you can with how it should be in the CAS, start the car and check it with a timing gun. I had to do this once after someone had snapped theirs off and thought the backfiring sounded cool but couldn't understand why the car was so slow... idiots....
Like I say, it IS possible
Cheers,
Andy
Pete, the CAS is driven by the star drive not the locating spiggot