Hi Barry
I eventually got the ignition sorted. I had to buy from the Fiat dealer as there are so many variants.
It wasn’t possible to pin down the right one on eBay. Some have a separate switch but mine didn’t, so I had to remove and replace the steering lock casting (£123)which includes the switch.
I haven’t had to change the original barrel and keys; or had to reprogram the immobiliser, which I was a bit worried about.
I took photos as I went along to help in reassembly. working out how to remove the various bits of the trim took awhile with a few “secret” screws. and the steering lock is secured with security “headless” shear bolts. These have to be removed with a hammer and punch and tapped round .
It was bit awkward and time consuming, but not beyond DIY.
I could provide photos etc when I’ve got enough time.
Nozzi