Cheers Chaps,
Turns out it was an alloy pin on the back of the ignition barrel that's sheared off.
The AA fixed so I put the key in to disarm the imobiliser & steering lock, then on the disconnected switch thats hanging down now - I start & stop the engine with a screwdriver
I went to a Vauxhall main dealers yesterday, they were talking £140+vat for parts and reprogramming ecus and keys. I've found a new replacement barrel and keys on ebay for under £20 where you just swap the chip from the old key into the new one.
Got most of yesterdays work done yesterday, even with the 1 1/2 hour delay.