I've never heard of the song, but I came across "Fish, Tin & Copper" used as a toast in the book "Deep Down" by RM Ballantyne 40 yars ago. And, oddly enough, it's the only thing I can remember about the book - no memory of story-line or anything else. Fish, tin & copper were the staples of the Cornish economy (was there no agriculture in Cornwall?).

RM Ballantyne is better known for his book, "Coral Island" which is itself better known as the book that William Golding wrote "Lord of the Flies" against (does that make sense?).

Coral Island: Boy heroes Ralph, Jack and Peterkin get marooned on a desert island and, keeping their upper lips stiff, maintain the British Way of Life until rescued.

Lord of the Flies: Boy (anti-)heroes Ralph, Jack & Piggy get marooned on a desert island and revert to savagery before being rescued.

I know which I think is a truer description of human nature.

Sorry: thread's crept.