A "shang-a-roosh" sounds to me like a compliment to an aggressive, high-spirited shipmate. And "the proper ju-ber-ju" is traditional nonesense words for the "right stuff" as you suggest. The Doggerbank Song is generally assumed to be newer than either the Great Lakes ballad or the lumberjack version, both of which are great songs.

Cheerily,
Charley Noble