Orval Fairbairn wrote:
snip


Canberra was a twin-engined British design for a high-altitude bomber.
The Martin Co. modified the Canberra into the B-57; the special
reconnaisance aircraft was the "RB-57D/E," which looked somewhat like
the B-57, but with much longer wings and different engines.

That's because it was a B-57 with much longer wings and different
engines. Actually there were two variants: one had four engines, two
monsters and two auxilliary engines IIRC.