Thank you for your replies. I have tried all the points made here till I am pulling my hair out. Dressed the wheel, turned the wheel in small increments, turned the arbour washer in small increments, used tape as spacers and bolted it down to the bench so that everything on the bench rattles. There does not seem to be a lot of side movement in either wheel (barely noticeable) and dressing the wheels has made them perfectly round. I have even removed both wheels to be sure the shaft is true and it runs perfectly which is why I am completely at a loss at what to try next. 😕