Leon. The difficulty with the rear suspension is the amount of travel available. With the trad chassis Morgan have never moved away from having the rar axle situated above the chassis, this means that rebound will always be limited and often the hit you feel is the axle hitting the rebound rubber blocks. They don't have a lot of movement in compression either but good dampers will help.
Chris444.
Peter Ballard has come up with something for the rear. It was originally marketed as the Suplex 5 link suspension but since Suplex moved out of that market all both the front and rear suspension systems are now made by Peter Ballard and Dan White (ex Suplex UK GM) and their company
Suspension Supplies Limited I have no connection other than being a happy customer.