Let's face it guys, Morgan should have converted to front, maintenance free, wishbones at least 40 years ago. There would have been no angst about the "update" in those days and would now be seen as traditional by all except flatrad owners. Regarding rear leaf springs it is worth observing that most light vehicles that still use live axles have long since abandoned leaf springs for coils.
The rapid sale of the ARP4s and the interest in this topic (5 link rear suspension) shows that new buyers and many existing owners are happy to leave some traditions behind if it means an improvement in comfort and handling.