Hi deltahotel,
Thank you for your considered response. I like the idea of getting hold of a UK TRE for the test and letting him contact the CAA - I had sidelined the TRE requirement for now since I felt it would be easier(money & logistics as you say), than finding a sim. You are correct that the other sim is in France. I have written to Airbus to enquire but other than initial clarifications, they have not properly responded yet.
Investigation coninues....