Mounting a M42 Jupiter-9 (a good FSU Sonnar 85/2 clone) on Nikon via a glassless adapter

I embarked on this project because my LTM Jupiter 9, a black LZOS specimen from 1987 while OK stopped down is rather soft wide open. Much softer than my older Kiev mount J9. I solved my LTM problem by getting a flawless KMZ 1957 optical block from Yuri, and swapping it out. Of course, it is nececary to adjust the shimming with the new lens/mount combo. (Gripping the lens at the front rim, the optical block simply unscrews from the focus mount; no grub screws to loosen. You cannot harm anything provided you don't lose the shim ring[s].) I am having fun with this combo on my Leica M3. The Jupiter 9 is hardly bigger than a 1.4/50 normal lens.

I decided to press the leftover, soft-wide-open optical unit into service as a special-purpose portrait lens for shooting older folk like me.

Again from Yuri, I acquired an M39 Jupiter 9 with a M39 to M42 adapter. From Mike at Kiev Camera I picked up a glassless (ie no infinity focus) M42 to Nikon adapter ($6).

The pictures tell the story: