Big thanks to Kevthefarmer.

George Wyndham had a brother Charles who was also a colonel and was the squire of my village, Rogate. James Norris as whipper-in to Col G. Wyndham's hunt confirms that we are talking (singing) about George. Bob Lewis who sang this grew up in Heyshott only a few miles from Petworth so there is a good chance his mother got the song through the tradition.
COVID permitting the Petworth-based Chiddingfold, Leconfield and Cowdray Hunt still have a trail-hunting meet in Rogate.