Ok, I have an update, I am still waiting for the cable which runs from the TCU to my bt antenna, but!

I have installed the TCU.

Initially it said "Activate Phone", so I "retrofitted" the module with SSS Progman v32. Which returned as successful.
There is now a red flashing light my MID display next to the TEL button, and the cluster says "please wait" if I push the tel button.
I then used inpa to turn on bluetooth and clear the error about the antenna not being connected.
I figure there is no point worrying about anything else until the cable turns up so I can actually connect the antenna but will let you know how it goes.

Tim