Thanks for that very helpful reply. Old cars - I started driving in '65 in a 100E Ford Pop before graduating to Minis etc. Since then, apart from totally rebuilding a 1984 110V8 Land Rover about 20 years ago (I'm familiar with prop shaft chatter etc), nothing. My current SLK55 is quiet!
I'll do as you suggest. Was about to take the drive shafts off and lengthen them by 10mm or so.
Regards