A little late reporting back but an update as requested.
My plan has come together. My long standing ECU woes are over. My car is now running perfectly with a re-cycled Ford unit flashed with a superb map courtesy of the factory (thank you very much indeed for your help). No pinking issues, full diagnostics and even my old rev hang niggle seems to have gone away. Also now that I have access to the map file I've managed to spawn some useful working spares as I believe this ECU is no longer manufactured.
Fortunately the Ford Visteon EEC-V donor units that Morgan fitted into these cars can be tracked down with a little detective work. However beware there are many similar units that look externally identical but have a different. From what I have deduced Ford used this unit over a decade ago for about a 2 year window only. It appears Morgan used the same unit a little longer. At least from 2005 to 2009 on the 4/4 Duratecs for the duration of their production to the best of my knowledge. As the original Ford donor vehicles are now coming to the end of their lives these ECU's can be picked up in good condition for only a few pounds, at least at the moment.
Obviously the Ford units needs to be re-flashed with the correct Morgan map. My dilemma was how to get the map in. The easy way would be to just connect the ECU to the car and flash it over the OBD. This may well be feasible but I was not prepared to risk attaching the donor unit to my car even to power it up until it had been successfully re-flashed. The risk that the unit perhaps had a subtle difference in build standard with so many similar variants was too high. Even with the correct unit there appears to be variation in map functionality across the Ford model range with respect to how the controls are allocated, so was not worth the risk. A little research indicated that the power and comms pinouts appear common across the ECU family but the mixture or passive and powered control lines appear not to be. The cowards option was to cobble it together so that it could be booted and flashed safely on the kitchen table.
Happy days
Sorry about the mess below.....
