Got the front bumper off - complete pig, lock carrier in service position and turned the engine by hand to get #1 to TDC.
Now if I set the cam sprocket according it it's marks (the 4Z pointer in the middle of the 2 "lugs"), a 6mm drill bit can be inserted quite some way. So fairly sure - the top is spot on.
Here comes the problem - the crank isn't. To get the crank to where it needs to go and fit the crank locking tool & the mark on the crank sprocket to line up with the mark on the locking tool, the cam moves out slightly, enough for the drill bit not to insert fully.
There is a reasonable gap (5 or so mm) between the 2 lugs that the 4Z pointer should be between and when the crank lines up - the 4Z is pointing to the one end of the gap (between the 2 pointers if that makes sense). i.e. for the crank to lock the cam has to go counter clockwise 1 or 2 degrees and the 4Z pointer is now on the edge of the gap, as opposed to the middle.
I was thinking of locking up the crank - cam is 1 or 2 degrees out, remove belt, turn the cam enough to insert a drill bit all the way and then loosen the 4 bolts on the sprocket and continue. Does this sound OK?
Oh - did plug VCDS before hand and the value in Measuring Block 4 (Torsion value) was 0.