And now the final installment to this thread.
One of the first things I do with an OTA is to check the focuser axis alignment to the center of the lens with my Glatter laser as well as the alignment of the lens assembly with the focuser axis with a high quality Cheshire eyepiece.
So here are a couple of pictures showing the laser spot on the back side of a mask carefully positioned over the objective. The mask has a small hole (~1/16" diameter) precisely in the center of the mask. The hole was precisely centered on the objective using multiple measuring points from the cell face plate I.D to the center of the mask center hole. I got to with +/- 1/64".
The results speak for themselves. The result was the same over the entire FT focuser travel and if I rotated the laser. This is one of, if not the best, of this type of measurement I've taken, especially impressive as this OTA is over 10 years old, has been through multiple owners, and outside over four years cycling through temperature extremes. Remarkable!
The Cheshire showed one single, well defined reflection spot right in the middle too.
Mechanical construction and long term durability does not get any better than this! Ok, except for maybe the paint...but still, that's over 10 years of harsh environment.
Well done Yuri!