Just a bit of experience of removing this unit and obtaining a correct replacement.
I contacted Melvyn but was informed by Mark in their stores they had a problem as the unit they sent to a customer was too large and they ended up rebuilding the original unit
The one on our car is a Magnetti Marelli/Lucas A127 as fitted to the Rover 800Si and Montego T16 engine.
The reason for the removal was noisy bearings which I intend to replace. I confirmed the noise was from the alternator by removing the belt and running the engine.
Now for the operation.
Disconnect the battery or switch of the power supply using the red key. With the car on ramps or axle stands remove the belt and the 10mm head adjusting bolt. Slacken the 13mm headed bolt securing the alternator adjusting bracket to the engine block to aid refitting.
Returning to the top slacken the top long retaining bolt 10mm head and 13 mm nut. You will need a long extension to access the nut as the 4 branch manifold restricts you.
Now you must support the unit before removing the pivot pivot bolt. My son supported the unit from under the car. Now you must turn the unit to access the three 8 mm nuts retaining the heat shield to the rear of the unit. Remove the main cable and the one spade fitting where the normal electrical plug is located (no plug) I left the radio suppressor plugged in. Then carefully lower the unit through the bottom of the car. Refitting is reverse but better with another to help to do the job as the route is restrictive. The heatshield is very well made and includes a second shield internally to protect the unit as it is very near to the exhaust manifold. Now looking for a 5 rib pulley as my supplier can only supply with V belt pulley and I would prefer to have a complete unit for a spare.
Never a dull moment with a Morgan..