Having fallen asleep once and run alongside the M5 demolishing bushes and the like I can confirm they are tough, really tough my then company car would have been in bits. Never fallen asleep before or since?
You can get a better front end by fitting the Suplex suspension and the wire wheels will give a bit of flexibility and additional springiness, all helps, the back end is the problem as this is not great in modern terms, I added spacer blocks and a pan hard rod which improved matters hoped the Norwegians or Pete Ballard might have come up with something, needs progressive springing and a longer travel then could ride the bumps better, in my biking days I had a Fournales air rear struts and that helped the ride a lot so I do not despair, one day Morgan will get the right idea although petrol motors may be banned by then.......