Its been almost a year, but I finally got the job finished this weekend.

A few useful bits of info for anyone else in the future:
- as well as the factory CC stalk and standard loom, you also need a separate long loom that extends it to the ECU on the passengers side of the dash next to the pollen filter
- BFS engine has the Simos ECU, and in the Haynes manual its the APF engine diagram that I referred to. Instructions from VW Teeside also don't list the BFS engine, but the BFQ listing was the correct pinout.
For the record the wire colours on the long extension loom and the positions they went into the ECU plug:
T121/67 - blue/grey
T121/66 - red/yellow
T121/69 - black/white
T121/68 - white
- its the plug on the LH (outboard) side of the ECU that the loom connects to
- I routed the loom from the ECU out under the plenum cover then under the air ducting and over to the drivers side to connect with the stalk loom
- The most bastardly bit was trying to get the terminal out of the main fuseblock (fuse 5) so I could insert the wire from the new loom. My advice to anyone else doing it at home is unless you have the special removal tool (VAS1978/4) or equivalent, then you're probably better to cut your losses and just join the new wire in using a crimp or solder. I persevered and ended up butchering the socket, then had to resort to solder anyway.

Hardest bits of the job for a newbie:
- working out how all the dash bits come apart
- interpreting the instructions when it doesn't quite match your vehicle and your engine code isn't listed
- removing the steering wheel airbag (use an old screwdriver heated then bent to 90deg and this video Volkswagen MKIV 4-spoke steering wheel airbag removal - YouTube )
- removing that damn terminal from the fuse block.

Very glad its finally working, and thinking I should stick definitely stick to doing mechanical stuff.
I also changed the timing belt this weekend and I reckon it was about the easiest one I've ever done - gotta love the single o-ring and 3 bolts on the water pump too
Couldn't work out how to change the spark plugs though (looks like the whole intake manifold has to come off) - but that's a job for later......

Steve