So as I was due to have my Comms 2000 looked at by Graeme, who advertises repairs to Comms 2000 on E.Bay, I mentioned it to him in a phone call, and he said that it could be a possibility that the fault was there.
So I made the 10 mile or so trip to see him today, and he stripped the steering wheel and Comms 2000 off, and did the indicator stalk repair to it that these units suffer from, and did a couple of other things, and then reinstalled the lot back together, and guess what?
NO FRIKKIN AIRBAG LIGHT.






Hallelujah.
So two things spring to mind here:
1. If your indicator stalk is of the, "I am not self cancelling on my own," variety.
2. Your airbag light is on and won't go off, despite you trying all of the other methods, then either send your Comms 2000 to Graeme via his E.Bay page, or if like me you live not far away, you can either take it to him already off the car for 20 pictures of HM The Queen, or he can do it for you, and do other tests for 35 pictures of HM The Queen.
Turned out that my Comms unit had been a replacement in the past, as my car is a 2002, whereas the Comms unit was made in 2004.

Work on my HDi continues.
Next, the cambelt and all the other stuff associated with it.