This mine is usually termed St.David's or Llandovery Consols. See J.R.Foster-Smith "The non-ferrous mines of the south Wales area", British Mining No.18, Sheffield, 1981, p.28, and G.W.Hall "Metal Mines of South Wales", 2nd ed, Kington, 1993, p.39. Penlantelych being the famhouse 400m east of the mine site. Hall described workings east and west of the road around NGR SN 783 332. When I visited the site a couple of years ago, I could see no traces west of the road - there have been large scale modern farm buildings constructed thereabouts which may have removed mining remains. In the wood east of the road is a quarry and various trenches and disturbed tips, all now throughly vegetated. Hall made no mention of Idris Treharne's explorations so it is good to learn of them. Do you know the exact location of the adits? - I couldn't positively identify them in the wood.