Wow 😮 If it’s the same John Gunn (Ben Gunn as we called him), then I was one of the Didsbury/PDHS/Magpie lot who caved with him in the early 1970s. I think it was 1973 that we first went into Water Icicle Mine. I have some photos of him and Ady Pearce in there and at Waterfall Swallet, a lot of memories 😀