okay - so bear with me thos ewho have been following the thread.. firstly the guys at HR Owen Maserati in Acton have been very helpful and doing their best - so I think them for that..
However, the bad news is that after replacing and balancing the clutch, and replaicn ghe engine mounts, the vibrations at 2.5k are still there !

They are less apparent after the new engine mounts.. but still noticable and need to be sorted. The improvement is less vibrations coming through to the cabin.. and generally it feels smoother under hard accelleration .. which must be the new mounts.. can't imagine what was wrong with the old ones..
Good news.

They think that it must be the torque tube (laymans terms, the driveshaft). Which by the way is what I had thought that it was int he first place.. I have dirven enough old british sports cars with driveshafts and u-joints, to know whent he vibrations are coming from the driveshaft.. albeit a torque tube version..
And as just described in the thread, it enables the engine and gearbox to be connected as a one piece unit.. the tube is the colid connection bolted to the back of the engine housing and the front of the gear box. Then down the centre of the tube is a driveshaft, splined at both ends as you would expect, and held in place by three bearings within rubber mounts.
This driveshaft must now be the cause of the vibrations. I.e. it is slightly out fo balance and therefore oscillating at 2.5k..
They are now applying to Maserati to get approval to replace the torque tube with a new and balanced one.
Will keep you posted as usual!
PS.. borrowed a QP on the weekend as mine was still in bits. Nice motah.. a bit American in suspension set up - there's thta unpleasant jelly feel to the ride like most American saloons.. Other than that I very formidable luxury family saloon..and boy does it catch the attnetion of passers by!
