To put it simply.

The song in its present form was a culmination of old folk song,
it was written and published in the book "woodcraft folk songs", by the left wing youth movement called the woodcraft folk.

the song was origionally in the form mentioned above 'ARE YOU MR RILEY'.

and as for the comment about being tought to kill coppers.
ah i wouldnt put it past the 70's era of the woodies,
there all commies anyway

love it.