You shouldnt have problems with brass unless you have alum in your rig too. Aulm & brass will cause oxidation. stainless is aok.
Is there a electrical box mounted to the motor or are the wire just right out the body of the motor?
As for the wiring, i would guess that one of the wires should have a white stripe, thats nuetral, black hot, green/yel ground.
other wise do you have a picture of the pump?