TY very much both Nuke and No7. It will be tomorrow before able to do anything further. Starting with blue tap as in last post. If no joy at that point, then will have to engineer (not a prob now as have video evidence if there was any suggestion of no problem with w/m & any poss of fee incurred).
Your bang on nuke, wouldn't go as far as taking top off, or even touching any screw as could invalidate guarantee, as am sure you both well know better than I.
Again, so grateful for all your trouble, input and help. Will get back tomorrow :-)