Hmm, as I stated - the schematic above matches my LTN-72 CDU and I also have CDU (3) from the first posting where the pinout does NOT match. Probably the CDU (3) above is what you have got, too. But I guess the basic functions are the same as are the internal electronics. As you discovered: Probably only some pins are swapped. Would be cool to see a picture of your illuminated CDU ;-)
Unfortunately I had no time so far, giving my CDU+LTN a try although the test cabling is prepared. Here for reference the two control panels I obtained/resuced over the last weeks to go with my LTN72-RH:
(A) A Mode-Selector panel, type 452100-02-03, serial 6825 from a scrapped Atlas airliner:
(
B) A CDU, imported from Rio/Brazil (AeroBay made a good hobbyists price); type 452090-02, serial 0265 and it came even with paperwork and test protocol dated December 2010 and the origin was a scrapped TAP aircraft:
Will post an update after first tests - but probably not before February 2021 due to the pandemic...