Whilst sorting out a holesaw to enlarge the focuser port I made a decision regarding which focuser I was going to use and then set to with FreeCAD to design a new mounting plate for it. I’d measured the outside circumference of the tube as 1122mm which gives an outside radius of about 178.6mm. I needed that to create the curved mating face of the mounting block. A short while later courtesy of my 3D printer I had this:
A quick test gave a good clean fit to the outside of the tube, but I needed some new longer bolts for fitting the focuser so ordered them (in stainless steel) via ebay, which I’ve always found a great place for getting nuts and bolts in small volumes.