re: Bullgine
Another quotation from an article that Q cited earlier, by C. J. Lovell (American Speech, v. 21, 1946, pp. 116-119).

"Clar de track, de bullgine's coming"
Negro Forget-me-not Songster, 1848, p62

I don't have that work available to me. It would be great to see the whole text.

Q writes,

"People knew "bulgine" was a Black dialect term." I dispute that, it seems to have been in general slang use by firemen, sailors, and especially railroaders, who have kept the word current (it came into the music hall and literature from these usages).
It had its origin in the Bull engine, a steam engine for pumping water, invented in Britain, but much copied. The OED gives this as the source; "Bull + enjine, and define it as "a locomotive or steam engine."
The Oxford English Dictionary quotations show its rather sudden adoption as a slang term in the 1840s, and its use in a novel and the music hall.

Naturally, there are plenty of words and idioms that are in general use now but that were once used mainly by a certain group. I see no evidence that "bullgine/bulgine" was "general use" during the period 1840s-50s in which these chanteys were most likely conceived. It's supposed later currency --amongst railroaders, hobos, and sea chantey enthusiasts-- is just that: much later, having been incorporated. You have repeatedly referred to "novel" and "literature" in generality, but I am concerned that you may have jumped to that from the one quote from STRAY SCRAPS. Here is the quote from that, in full:

Evincing, we are inclined to believe, evidences of
pugnacity in various sets-to with his brother bootblacks,
and probably making himself agreeable to his officers by
jumping Jim Crow, playing on the bones, and imitating
the 'bull-gine,' he was at length honoured by being
permitted to march in a ' forlorn hope,' and unquestion
ably earned a commission by butting down a score of
the enemy.

It is a caricatured depiction of "Othello," a black man, using the minstrel music stereotypes. "Bull-gine" is in quotes, as to say it is not a word the author himself uses.

The vast majority of other reference fall in the context of evocative-of-Black speech. When you say "music hall," don't you just mean "minstrel songs"? If it walks like a duck...
I do not see on what grounds you say that "it came into the music hall and literature from" ..."general slang use by firemen, sailors, and especially railroaders".

100 years from now, "shawty" may be thought of as just a dialect pronunciation of "shorty"...or it may even be incorporated as mainstream slang for a friend or sweet girl...but wherever it ends up that does not change that if I use the word nowadays I am making conscious reference to something Black.

On another note, I found a rather sketchy but potentially relevant reference to the trope of "Eliza Lee -- marry me". In a Black American song collected by Odum in 1911. here's a link. Chorus runs:

Ha, ha, Miss Lizzie, don't you want to marry me — marry met
I will be as good to you as anybody — anybod-e-e,
If you'll only marry me.

I don't think it's related to "Clear the Track" -- just more fodder for the "Eliza Lee" theme. It is relevant to me since I assert that it is such cliche themes that make up the freely-varied material that went into building chanteys.

I also want to quote this passage from the article:

The songs in this collection are "negro folk-songs," in that they
have had their origin and growth among the negroes, or have been
adapted so completely that they have become the common songs of
the negroes. They are "folk-poetry which, from whatever source and
for whatever reason, has passed into the possession of the folk, the
common people, so completely that each singer or reciter feels the
piece to be his own." Each singer alters or sings the song according
to his own thoughts and feelings. How exactly this applies to the
negro songs may be seen from the explanations which follow, and from
the study and comparison of the different songs. It is not necessary,
therefore, in order to classify the songs as negro songs, to attempt to
trace each song to its origin or to attempt to determine how much is
original and how much borrowed. Clearly many of the songs are
adapted forms of well-known songs or ballads; others, which in all .
probability had their origin among the negroes, resemble very strongly
the songs of other people; while still others combine in a striking way
original features with the borrowed. In any case, the song, when it
has become the common distinctive property of the negroes, must be
classed with negro folk-songs. Variations of negro folk-songs among
themselves may be cited as an illustration of this fact. Likewise there
is abundant material for comparing with well-known folk-songs or
ballads of other origins...comparisons may be made with ''Jesse James,"
"Eddy Jones," "Joe Turner," "Brady," "Stagolee," of the hero-songs;
"Won't you marry me?" "Miss Lizzie, won't you marry me?" "The
Angel Band," and others similar to some of the short Scottish ballads
and song-games of American children; and "I got mine," "When she
roll dem Two White Eyes," "Ain't goin' be no Rine," and many others
adapted from the popular "coon-songs;" together with scores of
rhymes, riddles, and conundrums. In any case, the songs with the
accompanying music have become the property of the negroes, in their
present rendition, regardless of their sources or usage elsewhere.

That is a fairly accurate to how I am approaching "Clear the Track," however, without necessary emphasis on Black ethnicity. While I clearly think originally Black paradigms of song are a main basis for the genre, after a certain stage it became irrelevant what the nominal ethnicity of sailors was; it was a sailors' (or workers') genre.
Substitute the word "sailor" for "negro" in the above passage! :)

Gibb