Hmmm……..according to the Boeing website, Condor were launch customer for the 757-300 – not Northwest.
It’s in use with rather more operators than the 767-400, mainly charter carriers due to it’s very low seat-mile costs, but a few scheduled airlines use it – including Continental.
It has a shared type rating with the B767, too. Not a lot of people know that. (In a Michael Caine voice) 😉