So I picked up the League Of Extraordinary Gentlemen: The Black Dossier in its reissued version from Gosh Comics today (they are having a Fatale signing and launch with Sean Phillips, as well as an exhibition of his original art) and indeed it comes with a vinyl single record, recorded by Alan Moore and Tim Perkins in the style of Elvis but credited to the fictitious musician Eddie Enrico, from Pynchon's novel Vineland.
I do not have a vinyl turntable.
But I know someone who does. Hopefully I'll pop round their house tomorrow.
Until then, here's a scan of the record in its case.
Troynovantum is derived from New Troy and was one of the many early names for London. The styling is based on that of London Reccords, a brand used by the UK branch of Decca for distributing its records abroad.
The record is attributed to Kapital Record of The Brillcreem Building, the address of which actualls holds The Brill Building, with a history of some of the most influential music publishers through the twentieth century.