The first two bikes arrived in Adelaide in May 1966 on MV Prt Vixidex. Both 250 Challengers. The engine and frame numbers were provided by the importer (Frank Galalary of All Make Motors). Definitely A, not B.
The third bike, also 250 Challenger, arrived in Adelaide in November 1964 on MV Arcadia. I know where this one is, but am trying to locate where the other two might be.
Cheers