@ceffyn you have to remember that it's a Land Rover, they can end up with enormous amounts of backlash,(clunks/clonks), in the drive train, every worn gear, spline, cv joint, axle to hub adaptor etc adds a bit to the backlash.
Have you tried applying CDL and the handbrake jacking up one front wheel, climbing under the transfer case, grab hold of the front drive shaft output flange and see how much angular rotation you get. The thrust washers in the centre diff assembly can wear really badly even to the point of allowing the sun and planet gears to ramp over themselves, but you will no doubt be aware that the clunks and clonks are much a part of Landy ownership.