Q, my copy is unquestionably at least the Third Edition because it includes prefaces to three editions as well as fifty, not forty, songs. If yours contains an additional version of "A-Roving" plus another preface by Hill, it must be a later edition. Such an edition exists and is dated by World Cat to "191-?"

Why Boosey published it as "Revised" rather than "Fourth" I can't imagine.

A more significant issue, however, is the authenticity of the shanty words. Hugill himself suggests that some of them, notably those to "Can't You Dance a Polka?" were written by Davis & Tozer. He thought they were too coy and sentimental to have been acceptable to the British sailors he knew in the 1920s, many of whom had been at sea for more than twenty years.

I'll say it again: Davis & Tozer credit Smith and the ships' officers for "airs" (melodies) and "airs of 'Chanties'" not "words" or complete "songs." And I have to believe that the shanties sung by Stanley Slade in 1950 came directly out of Davis & Tozer - why, I don't know. Were these the words he sang at sea around 1900? I don't know that either.