3DR E3D v6 holder with pneumatic valve top

The print quality of my E3D delta printer had gone progressively downhill. I investigated and discovered that the hot-end was not being tightly held in its bracket. Instead there was a significant amount of lateral play causing layer misalignment (first grey print).
I liked the look of DragoslaV's 'E3D V6 holder for 3DR' but I had bought the version with a separate pneumatic valve to hold the Bowden tube.
I used Blender to graft the valve socket from RichRap's original J-head design onto the