I haven't looked at Clement's _Manevilins_ (though I'd like to - it's just not top priority) because it specifically says it does not contain chanties! :0

However, it would probably be best to look there before speculating too far.

Since we don't know (usually) what we are getting from Lloyd, I'd not assume his rendition was necessarily anything directly given over to him by a traditional singer. When he recorded Blow Boys Blow in the mid/late 50s, he definitely had access to Doerflinger's volume and he used it—not necessarily for this song, though he surely looked at it!

Doerflinger's presentation is mostly from William Laurie, born 1862 in Greenock, Scotland. First went to sea circa 1876. Doerflinger recorded him in 1940 at Sailors' Snug Harbor (Staten Island, New York). A couple lines from the singing of John O'Brien (also of Sailors' Snug Harbor) are mixed in. In the Appendix, Doerflinger gives variant versions of the chorus as sung by O'Brien and by Capt. James P. Barker.

Doerflinger also notes that bits of the song's text can be found in these sources:

1926         Boughton, Captain George P. _Seafaring_. London: Faber & Gwyer Ltd.
1906         Bernard, D.H. "Sea Songs and Chanties." _The Nautical Magazine_ 75. 431-435.

Hugill says there are bits in:
1953         Shaw, Captain Frank. _The Splendour of the Seas._ London: Edward Stanford Ltd.