I found another mentioning of "the Air 'Rattling Guns'" for the melody in a recorded performance of Westlin Winds by The Voice Squad. Someone above cited the same by "Phil Callery & The Long Wave Band" - well, Phil is member of The Voice Squad as well.

To add to the confusion: John Moulden here suggests the name "Rattling Guns" might itself have resulted from a distortion of the first line of "Westlin Winds"... (if I understand that correctly).

However, he also refers to Len Graham, wo can be found singing the song to a tune quite similar to Gaughans variant.

But I could not find any notes to an air "Rattlings Guns" online.