The October 2017 edition has mention of the Colin Guile Collection which are colour slides relating to:
• Ysbyty Cynfyn: Ref. No. CGC/01
• Cwmbrwno Lead Mine: Ref. No. CGC/02
• Llawr Cwm Bach Mine, Elerch: Ref. No. CGC/03
• Bryntail and Y Fan Mines: Ref. No. CGC/04
• Plynlimon Lead Mines: Ref. No. CGC/05
• Eisteddfa Gurig to source of R. Wye, Nant Iago and Nant yr Eira Lead Mine: Ref. No. CGC/06
• Cwmsymlog and Cwmerfin Lead Mines: Ref. No. CGC/07
• Bron Floyd Lead Mine: Ref. No. CGC/08
• Banc y Darren Mine: Ref. No. CGC/09
• Llywernog Lead Mine: Ref. No. CGC/10
• Nant-ddu and Dwfngwm Mines: Ref. No. CGC/11
• Cyneiniog Valley, Tynant, Bwlch Glas Lead Mine: Ref. No. CGC/12
• Neuadd Llwyd Lead Mine: Ref. No. CGC/13
• Hendre Ddu Quarry: Ref. No. CGC/14
• Minllyn Quarry: Ref. No. CGC/15
• Wemyss and Fron-goch Mines: Ref. No. CGC/16
• Glaspwll and Pistyll y Llyn: Ref. No. CGC/17
• Grogwinion and Gwaithgoch Leadmines, Pontrhydygroes and Rhoswydol, Mont: Ref. No. CGC/18
• Aberllefenni Slate Quarries: Ref. No. CGC/19
• Ratgoed Quarry: Ref. No. CGC/20
• Abergynolwyn Quarries: Ref. No. CGC/21
• Pantyspydded: Ref. No. CGC/22
• Tarren y Gesail Quarry: Ref. No. CGC/23
• Gwynfynydd Gold Mines: Ref. No. CGC/24
• Bryntail Mines: Ref. No. CGC/25
• Pensarn Mine, Taliesin: Ref. No. CGC/26
https://rcahmw.gov.uk/royal-commission-archive-library-bulletin-of-newly-catalogued-material-october-2017/?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+HeritageOfWalesNews+%28RCAHMW+Heritage+of+Wales+News%29 If you follow the links on the above web page you can (eventually) get to the images themselves.
Dave