Thanks for interesting report Robbie. Although facts cannot be denied I'm still sceptical of the need and use of steering dampers. Off road vehicles including my Land Rover have them for obvious reasons but for road only use I cannot help but imagine they just hide a steering problem, not fix it at source.
You didn't mention in your search for improved steering comfort if you had camber, toe in and maybe castor checked. None should have induced wheel vibrations but may have accounted for tyre wear between the wheel balance sessions.
Modern Classic Morgans don't generally seem to need them, nor do they suffer from bump steer given the long track rods, so I have to wonder at the ones that do benefit from the fitting of steering dampers
