Marsch des Grenadier-Regiments Nr. 2 des Königs von Preußen

Armee-Marsch Nr. 19 von Anton Dörfeldt
aus der Zeit König Friedrich Wilhelm III. von Preußen (1770 - 1840)
Ausführende: Heeresmusikkorps 6, Hamburg,
Leitung: Oberst Johannes Schade
Aufnahme von 1971

[@Bluehawk2008]

If this is AM II 19 by Dörfeldt, I think it might refer to Russia's St. Petersburg Grenadiers (later of the Leib-Guard) which had Friedrich William III as its chief. This is a different regiment than Prussia's 2nd (1st Pomeranian) Grenadiers "Friederich Wilhelm IV". You can find recordings of this march playing here in your video labeled "AM II, 19 Marsch Des Russischen Grenadier-Regiments König Von Preussen".