That will be some sort of bronze Peter, what type can only be guessed at, unless there is a stamp on the end of the bar, PB1, PB2 etc.
With reference to the aircraft industry, it would not have been used for that, the controls of metals and materials going into engines wouldn't have allowed it to be used in parts manufacture, they have too stringent a control over that. Maybe it had been used for jig making or some such other use off the aircraft.
John