Well - I've been looking more closely at my copy of Naval Song Book. It is undated and I assumed it was the 1945 version.

Closer inspection, however, makes me think it is the earlier version.   
The previous owner was an officer in WW2 which is why I assumed the 1945 version. A little research, however, showed me that he was born in 1896 and worked his way up through the ranks.
He was in Malta (Warrant Engineer, HMS Warsprite) in 1928, and the book contains a concert programme that could relate to that period (it mentions the Bastion Club, which suggests Valetta)
Also, the contents of the book correlate well with the late-Victorian/Edwardian song books, (I'll post the index in the Victorian song indexes thread,) and the latest copyright acknowledged is 1902.
So - - I think I have a published copy of the Robbers' Retreat from the early part of the century.

I could be wrong, of course, but at least there's something that can be verified.