I hoped it could be guessed as I gave some information that it has a bigger brother and than I also has one for another brand to try out :-)
And also that the lenses seems to be APO corrected.
But it is a scanner Nikkor ED which was used for either a LS-4000 or LS-5000 scanner. A 7-element ED lens.
The bigger brother which I will get soon is one used in the CS 9000 scanner and this lens is a 100/2.8 with 14 elements and lot of ED glass.
Lenses are still relative cheap compared to performance but prices seems to have gone up since 2016.
Little and bigger brother her (with example of with the 7-element lens can do):
https://www.closeuphotography.com/scanner-nikkor-ed-7-element-lensAs these scanners also use a IR-scan for scratch removal.....lenses may be usable for IR-also? .....but not sure about that......