Hi Cain,
Many thanks, those two photos explain a great deal. I had assumed the MT75 had an extended end housing like the Mazda box (and most other gearboxes I have had). However there does not seem to be anywhere on this photo that would take the standard non-Librands MT75 mod. I think I have not yet owned a Morgan long enough not to be surprised by some of the little idiosyncrasies that crop up. I assumed an MT75 gearbox was and MT75 gearbox and that was that. Silly me.
Thanks again for the photo - a great help.