Today John rang and said that he had would have to abandon those plans. It was too difficult to manage the 4x2m panel while the cutting and re-glassing was being done. Instead he thought he could locate an aluminium extrusion purpose built for pop-top roofs. It has a curved profile and will act as a frame for the roof panel. A lower section of frame will hold the top of the wall and allow for a seal between wall and roof.