This mine is well documented in Memoirs of the geological survey vol. XVII-The lead,zink,copper and nickel ores of Scotland by G.V.Wilson 1921 page 130 and is on the old series 6" map Renfrewshire XI SW dated 1898, You can view this on the national librey web site through the map room. There should be some evidance of mining at NS353614 and NS352615. Have fun JeremyL