Amnesia

"It was a dark and stormy night" -- aside from the obvious meaning, this is also a reference to the (in)famous opening line of the novel "Paul Clifford" by Edward Bulwer-Lytton.

"The first mate, the bosun and me" -- the 'first mate' is the second-in-command of a sailing ship; the bosun or boatswain was the most senior member of the ship's deck crew.

"from Bristol to the Ivory Coast then on to Jamaica" -- the Atlantic slave trade was an example of a 'triangular trade'. Ships from British ports such as Bristol carried British manufactured goods to Africa, where they were exchanged for slaves. The slaves were then carried to the West Indies, where they would be sold to sugar cane planters to work on plantations there. The ships were then loaded with sugar and rum for the journey home to Britain. The profits from the sale of West Indian products were used to buy more goods to be traded in Africa, and so the trade continued.

"Down in the hold there is no sound" -- the hold of a slave ship would have been filled with slaves.

"We're taking rock'n'roll to America" -- rock and roll derives from music made by American Blacks, which in turn was based on the rhythms and sound of African music; the ship in the song is clearly a slave ship, carrying Africans -- and their music -- to the Americas.

"The crack fields of Bolivia" -- Bolivia was an exporter of coca paste, used in the production of cocaine and crack, a variant form of cocaine.

"Burning White House" -- the White House in Washington D.C. was partially burned by British troops during the War of 1812.

"Shining Path" -- the Sendero Luminoso or Shining Path were a Maoist revolutionary movement in Peru during the late 20th century.

"Americay" -- the Mekons sometimes use poetic variants of words ending in '-a' for rhyme purposes; they do the same with 'California' in the song "Brutal"

"Eric Burdon" -- lead singer of the band "The Animals"

"stunned in Mississippi on The Animals' US tour" -- during the band's tour of the US, The Animals were violently expelled from the town of Meridian, Mississippi by local racists because of the band's promotion of Black music and the fact that the band had a Black assistant.

"Mardi Gras Indian" -- Mardi Gras Indians are Black revelers in New Orleans who dress in costumes loosely-inspired by Native American clothing at Carnival.

"Segregation" -- refers to racial segregation in the United States, when schools, businesses and facilities were divided along racial lines, and Black people were denied access to facilities reserved for Whites.

"1964" -- a pivotal year in the civil rights movement. The Civil Rights Act of 1964 outlawed discrimination on grounds of race, color, religion, sex and other criteria.

"wah-wah" -- a wah-wah pedal is a guitar effects pedal used to create a distinctive sound

"blackface-painted" -- this probably has a double significance; the song as a whole deals with racism, particularly in the context of music; blackface minstrels were White performers who painted their faces Black, performed music supposedly derived from Black music, and acted out racist caricatures of Black people. The last verse, however, has a military theme, and soldiers may also paint their faces black on night operations. The phrase is probably intended to evoke both meanings.

"gringo" -- Latin American slang for a North American; "gringo military" suggests an American army, probably an invading army in a foreign country.

"Led Zeppelin" -- successful British heavy rock band

"Marine Corps" -- the US Marine Corps, one of the arms of service of the American military.

The final verse of the song, with its references to "Up the river" and "Floodlit jungle" may be intended to evoke imagery associated with the film "Apocalypse Now" and, in a broader sense, the American involvement in Vietnam. The verse appears to suggest that rock musicians are a metaphorical invading army: a "heavy metal Marine Corps".

Both of the previous comments are relevant. Buried in the layered metaphors I also think there is an idea that the development of rock and roll is a kind of "triangular trade" recapitulated: derived ultimately from the musical traditions of enslaved Africans, exported from America to the British Isles and then re-exported by others including the Beatles, Led Zeppelin and, yes, the Mekons. The punk-inflected sound of the Mekons may seem far removed from African roots, but perhaps they are momentarily "forgetting to forget to remember" its ultimate origins. Possibly with some uncomfortable intimation that the entertainment industry of rock might participating in a form of continuing colonialism. Overall, I think the meaning is deliberately ambiguous and suggestive of multiple possibilities.

"Americay" also occurs in at least one Irish folk song about emigration