NB: the ‘Raymonda’ bit starts at 1.59″ – I’ve coded it to start there automatically, but if it doesn’t, use the scroll bar to skip to that bit.

On a trawl through Hungarian music on IMSLP this morning, I saw a little phrase leap out at me from a page of Hullàmzò Balaton Op. 33 by Jenő Hubay, that looked identical to a bit of the coda from the Grand pas Hongrois from Glazunov’s Raymonda. Double-checked and double-checked, and sure enough, it is. Hullàmzò Balaton (The Waves of the Balaton) is apparently a folk song/csárdás that pre-dates both Hubay and Glazunov. Any more comments from Hungarian speakers would be most appreciated.
There’s an even more spectacular recording on this Youtube video (‘Raymonda’ starts at c. 2’42”)