[BlueRubber]

Update:

I replaced the transmission mount ( connects auto box to front subframe ), this part was well worn.
Also replaced the engine ‘pad’ ( engine mount behind right hand drivers side wheel ), this part looked to be in good condition, but replaced it anyway.

Unfortunately the car still has the same symptom.
The clonk sound/judder always co-indices with the gearbox changing gears, which it usually does very smoothly, except in the narrow circumstances mentioned in my first post.

The only engine mounts that haven’t been replaced are the round front and rear ones.

Any suggestions on what else I can do to try and solve this issue?