Re Mrr's note, I think 'coke' for cocaine predates the song. Some of Agatha Christie's books written around the same time use the word 'Coke' for cocaine, including the upper-case initial. Good job it predates Coca-Cola's lawyers...

So it looks like the body of opinion is on it being a druggie song. Nice to know I can get the sex, drugs and rock'n'roll into my local folk club (or 2 out of 3 anyway :-)

Cheers for the feedback folks,

Grab.