So, had a bit of time this afternoon to have a look. Took the back wheels off and checked the springs are intact, while there checked the rear and front drop things are tight. The half shafts have a bit of horizontal movement, is this normal? Hope it is. Nothing seems loose. Used my new Christmas present to tighten the wheel bolts, very satisfying. 
The noise is worse with the top up, that means the clunking is probably Mrs MikeH banging her head against the roof lining, super tip for MikeH, for your going out nocturnal adventuring leave the roof open, simple