Complex sentence: The design was tested on a third-scale glider known as the A.W.52G but the war ended and the bomber project was dropped but received a contract that would allow them to produce two prototypes for evaluation nominally for a mail carrying aircraft.
Split into simpler sentences: The design was tested on a third-scale glider known as the A.W.52G, but the war ended and the project was dropped. However, Armstrong Whitworth then received a contract that would allow them to produce two prototypes for evaluation, nominally for a mail carrying aircraft.