I can partly answer your query about the 1960 pic "3 Hunslets, Penrhyn Quarries". Not all are Hunslets. This is the "scrap line" at Coed-y-Parc workshops, alongside the Penrhyn main line. Front loco is a de Winton (don't know which one, perhaps Kathleen?), then Manning Wardle Jubilee 1897, then, just visible, is what I think may be the chassis (only an outrigger or rear buffer beam visible) of Hudswell Clarke Bronllwyd (whose boiler was in use on Pamela), then Lilla (with boy on footplate), then one of the cabless Hunslets, and the rearmost loco is Kerr Stuart Sgt Murphy.