Fixed!
5 days....
Replaced rear wheel/axle bearings, crown wheel, pinion and all other associated bearings in the rear diif.
Front - replaced crown and pinion plus their bearings only.
Now it's quiet again.
Just wonders all over the road now. Maybe they didn't check the alignment after the job. Small-fry problem.
Jeez it's nice to have a car back that doesn't cause embarrasment in the traffic ... the problem was so loud that people would look....
All good now!