Regarding mgahans post #9520, the signed document states "The Southern Cloud was a sister ship to the Southern Cross and they are identical."
The Southern Cloud, built in 1930, was an Avro 618 "Ten" a licensed-built Fokker tri-motor. Avro modified the centre motor mounting to accommodate British airworthiness requirements. The Avro "Ten" was powered by more powerful 240-hp Armstrong Siddeley Lynx motors.
The Southern Cross, built in 1926, was a Fokker F.VIIb/3m, which began life as the "Detroiter", a Polar exploration aircraft of the Detroit News - Wilkins Arctic Expedition. The Fokker was powered by 3 Wright J-5 Whirlwinds, producing 220-hp each. Fokker also sourced some cockpit instruments from manufacturers different than those on the Avro.