Since I got back from Holiday I've been to see the situation. The top flat outer edge of the belt has become ribbed and is rapidly breaking down. It's also become worn at an angle. There's absolutely no sign of any contact between the belt and casing.
A visiiting mechanic with loads of experience on scooters said that in his opinion the problem was with the variator. He was convinced that the problem is in that area. So I found a second hand one local ish and its been fitted along with a new Suzuki belt. I saw it turning and to my eyes it seemed tighter and less floppy. Richard will be back on the road tomorrow. All we can do is put some miles on then take another look. The first long ride will be to Duxord and back so that's the perfect test run.

Sorry to any earlier readers, for some reason a sentence had gone AWOL and it made even less sense than my posts usually do.

did that fix the problem mate ?

Yes worked well.no.more issues.We went on. another tour of Germany without a problem.