Torr
Well done on the new scope.
One point. The mirror clamps should not be tight. They should be set so the there is a small gap between them and the upper surface of the mirror. I am not familiar with the cell assembly on these scopes, but any well designed cell will hold the mirror inplace without the clamps being tight.
Although your mirror looks like a solid chunk of glass, even slight pressure on it wll cause deformation and turn your stars into little triangles. If you look near the bottom of this document (
http://www.astro-baby.com/collimatio...on%20guide.htm ) there is an example of what this looks like. It is best seen with a defocused star. I tightened my clips on my old 12" by only 1/2 a turn and it dramatically degraded the performance.
Usually upgrading springs is the best solution for a mirror shifting while moving in alt.
Malcolm