As far as I can remember, the tune sung by Geoff Hardman, mentioned by George Henderson above, goes like this:
X:1
T:Spotted Dick
M:4/4
K:C
G, |C3/C C3/E G3/G G3/E | F3/F A3/F G3 G|
G3/G ^F3/G A3/G E3/C | D3/D ^C3/D E3/D B,3/G,|
C3/C C3/E G3/G z E | F3/F A3/F G3 G|
G3/G G3/G G3/G G3/G | G3/G A3/B c3 |]