On the back of the engine block, where the oil pressure sender screws into the block, you will find a casting symbol. If the symbol is CF, you have a US manufactured motor. If the symbol is GF, you have an Australian motor.
Since your motor is rebuilt, the rebuilder could have painted it black. But, yes, originally, the late model Austrlain Clevelands were painted black with silver valve covers & air filter assemblies.
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