I spent the summer of 1974 working as a barman at the Old Dungeon Ghyll Hotel in Great Langdale in the Lake District. This was, and still is, a famous and long-established haunt of outdoor folk. I had been recommended for the job by an EUMC friend, Chris Hall, who at the time was the Assistant Manager. The Manager was a singular chap named Alwyn Darrel Carr (ADC), who ran the hotel with his wife. He was not universally popular, but I got on well with him, and he would encourage me to take the guitar into the bar and entertain the troops, so to speak, when things were not too hectic. "Bumblers" was a local term for the tourists who flocked to the place (Ambleside was known as "Bumblethwaite"), and the song just sort of fell into place.
The campsite warden at the time was a chap called Dave Guest, known as Trog; who went round the tents in the morning to collect the camping fees. This ritual found its way into the song, and Trog was one of those who initiated the practice of passing the Mountain Rescue collection box around the bar when I sang the song. (The Team also get a mention; and anyone who worked at the ODG was pretty much regarded as an honorary member - you were always likely to end up taking phone calls or helping out with a stretcher carry.)
ADC and Trog are, sadly, no more; but I recently learned that the song is still performed there, and the box still goes round! After 37 years, I feel that’s pretty good going...