Hello Richard,
Sorry to hear your news - I was fearful that I was going to face the same. My M3W made a heavy metallic grinding sound whilst travelling at 55mph - instant loss of power.
Got recovered home - eventually & subsequently arranged collection by MMC - for investigation.
M3W was in Malvern last week - picked it fixed on Friday afternoon.
I managed to get away with just a snapped valve - £2000 all in.
During the week Morgan confirmed that they had purchased loads of additional spare parts from S&S - also they had a good stock of spare engines (just in case).
MMC is now shutdown this week - I am sure BHM will find all the necessary spares, on their return.
Fingers crossed for you.
Andrew