737 EFIS CDU
replica but easily driven. might be ideal and looks like the real thing - could be ideal! You could even set it up as active ))
https://www.ebay.com/itm/CDU737/1231...sid=m570.l1313
747-400 CDU
Is what you MAY really want (and you could make an offer to get it cheaper), however driving the display might be difficult... saying that it would look impressive!
https://www.ebay.com/itm/Honeywell-Control-Display-Unit-CDU-from-retired-Boeing-747-400-jet/283055079754?hash=item41e765c14a%3Ag%3AnekAAOSw7NtbWSuO&_sac at=0&_nkw=boeing+cdu&_from=R40&rt=nc&_trksid=m570.l1313
767-300 CDU
Original as well... although you might have to persuade them to ship to Europe
https://www.ebay.com/itm/BOEING-767-300-Control-Display-Unit-CDU-As-Removed-P-N-4038170-905/253741899709?hash=item3b14321fbd%3Ag%3AokYAAOSw7VRbQ9m-&_sacat=0&_nkw=boeing+cdu&_from=R40&rt=nc&_trksid=m570.l1 313
I'm not an Engineer but I suspect the first option is your best, the other two may be impossible to drive without further hardware (basically half the avionics bay
).