Didn't the DC-1 and DC-2 have the same nose and wing sections?
I know that they weren't the same, but I've seen a picture of a DC-3 with a DC-2 wing. Appearently, it actually flew in China during WWII...
As for the Airbus/Boeing/MDD:
I would say MDD because it never built a widebody or extendbody twin-jet (Airbus A321 and A300/310/330; Boeing 757 and 767/777). The closest MDD ever got was a proposal for a twin-jet DC-8, a proposal for a twin-jet DC-10 and actually building the MD
Those who fail to learn history are doomed to repeat it in summer school.