I wish I could find two people to agree on the best spring / shock combination.
My 4/4 grounds a bit at the rear.
Donald. Can't remember what year of manufacture your 4/4 is. Around 2011/12 Morgan had to find nother supplier for leaf springs due to the British manufacturer closing. (I believe British production has now re-commenced). During that period they had a batch of rather poor quality rear springs, as I and several Australians can attest

Suplex now make a new design of rear leaf springs that are assymetrical to limit tramp. Also in the news there will be a new kit rear coil conversion kit from Suplex that should be released by Autumn. A pre-requisit of the rear kit is that the front Suplex kit be fitted as it will be tuned to give the best results in conjunction with the front kit.
I have no idea of the price at the moment but I have been told it takes about a day to fit. Final testing of a kit made using the construction jigs is underway on a 3.7 Roadster, the most powerful car available for testing.
I understand that Williams will be one of the approved dealers.