a purely 'good will' harness replacement as you've described is becoming extinct...as MB has put serious efforts to manage its warranty costs

...seems like you'd have to get your case into the top 1% consideration pool- - -by possibly putting in an order and deposit $$$ in for a new MB or....contacting an influential MB-type to put in a good word for you ie as suggested by Donnie

good luck and let us know what turns out
-fad