Just an update on the situation.
1) I met-up with Joe Latter (my source) and now have a video of him singing the first two verses.
2) whenever I sing in sessions or clubs I ask for information - except one night when a guy came up and told me his father grandfather and greatuncle all used to sing this. "Gimme" says I. "Oh I only reconised the tune the tone and the 'Royal Artillery' in the chorus"!!!
still - that is one more leg on the stool.