OK, I've looked at the Spinners' Songbook (no publication date but internal evidence suggests after 1964. Published by Essex Music ) version. The attribution is "new words and new music by Francis K. Bosworth" which I believe is the name given to the group's own authorship as Paul Campbell was for the Weavers.
The rubric says: "this fo'c'sle song was collected in part from a retired sea captain's widow by Jaqueline McDonald. Hugh Jones has added a verse and adapted elsewhere. The ship, Captain Newlands and the Black Ball Line are all historical figures. "Blue DBs" and "lime juice touches" are there but not Ulm's third verse. Copyright 1964 Essex music. It mentions its reputation for speed but doesn't mention cargoes.
RtS