GTI Engineering

Hi - I'm starting work on a nice C-reg cabbie modified by these people.
The previous owner has taken wire-cutters to the immobiliser (nightmare) and hacked the dash.
So I'm on the lookout for a replacement dash (as well as seats).
And trying to reconnect the wires which the immob would have separated.
Is there a central record of which cars were breathed on by GTI Eng?
Advice ps - is there anything special to watch out for when firing it up for the first time?
Thanks guys