I had mine out last night to see how well it mated up with a 35 year old Vixen SP mount as a system (very well actually) and the skies were actually rather calm. I had it up to ~200X with my Denk II viewer and the image of Mars, though small, was first rate and very sharp. I specifically looked for AD but did not really see anything overt (though there is always speculation as to what the prisms in the viewer are doing to the light cone). I had to focus carefully but there was no ambiguity when focus was found. An excellent view. A quick star test showed no visible coma or astigmatism.
My older, "gold tube", unit does indeed have excellent and smooth optics. I just completed making another DPAC Ronchi screen and LED holder with a smaller diameter LED (which lets me get the centers of the source and return beams closer together) and decided to shoot new DPAC images of my sample 120ED while I was messing with it. Attached are the results for inside, outside and at focus with white, blue, green and red colors, left to right in each image.
This is a very good lens, with an excellent edge, functionally a little overall under-corrected in green, with best correction falling somewhere between the green and blue (blue lines are almost straight). You can see mild spherochromatism at work by looking at how the lines bend in opposite directions between the red and blue lines in each image set, except, of course, the at focus images. Speaking of the at focus image set, you can clearly see that, with this sample lens, the red and green focus positions fall very close to each other while the blue focus position is slightly removed from that of the red and green. You can also see that in the inside/outside of focus images but not as dramatically (visually, the blue focus "error" is not "dramatic" at all, being invisible to me except on bright stars and Venus at high power).
So brisguy, your lens has a fine pedigree and should perform very well indeed if it was properly made.
Edited by Jeff B, 05 January 2021 - 02:22 PM.