Finally replaced the accumulators last weekend. Had the rear end on ramps, only 12 nuts total to remove and replace; but I took me almost two hours - had to take a short break because the dripping hydraulic fluid smells so awful
!
I checked out the accumulators by inserting a long 2mm alen wrench to the input line from the shock absorber. The wrench stopped at about 1" inch from the opening of one, but went all the way in on the other
So I've been riding on only one air cell. That might explain why it had always feel rougher when loaded with passengers on the rear.
The shock towers are still bone dry; so I just installed new cells. Took the car out for a spin, it rode much better in terms of both comfort and handling!
Thanks all that have made this possible,
Frank.