You could try and find an alternator that is the same size and does not rely on ecu for info to make it charge,there is a specialist in tyne and wear in Rolands Gill they may be able to advise you.
Cost : Little as possible.
Thanks : To those who by their generosity my build has progressed.
Its a handmade sports car not a flaming kit car !!!
If at first you dont succeed,avoid skydiving...
No parachute require to freefall,only if you want to do it twice.