Hi Mart. Welcome to TM and Morgan ownership. I'm sorry to read of your problems and some others have experienced the same problem. I had No.18 for a few months and it is a great car but old it before MOT was due. What number is yours?
MR11MOG, I think, had the same problem and ended up replacing the ECU from memory but I'm sure he can fill you in more on this. There is a thread on here to about it too.