Nice reasoning there! My own guess is that Hal and Tow is Heel and Toe (dancing) and Jolly Rum Below is another merrymaking reference.
All translated to the land from the sea of course (sailors have to go home sometime!!) Why anyone would want to dig up arcane meanings when the easiest answer is there I do not know . . . .some people have great trouble seeing the simple in life . . . cheers, Sieffe (who has been singing this rubbish for 30 years! . . . .)