Andy,
firstly is everything greased properly and are the tyre pressures correct. The tyres play a far bigger role in the ride than on modern cars as they are inflated to 22.5 psi.
Some folks on here have then gone the Suplex routes other just better shocks. Not sure what Mr Mog fixes as shocks these days but the originals were usually rubbish.
This may help but I am sure this thread will run & run as others on here comment.
http://www.gomog.com/allmorgan/front.htmlhttps://sites.google.com/site/morganatica/suspension/springs-progressive-rising-rate
