I started the morning by making sure the cylinder was sitting on the target face of the bed with the valve face perpendicular to the bed. Then I fitted the piston after packing it with soft packing. When I had that in place I put the soft packing in the piston rod gland and then mounted the cylinder on the bed. Once that was done I used the piston rod to mark the end face of the crosshead, drilled and tapped that 2BA and then fitted it with the piston rod engaged. As expected it is a tight fit but that was to be expected and can be adjusted in subsequent fitting operations. Lastly I refitted the normal everyday cutter in the vertical mill.
Once again, steady progress and no mistakes..... I shall take a view tomorrow when I start.