and put SH in front of themI'm another big user of geograph, just tested your link at didn't work for me..I would go to main pagehttp://www.geograph.org.uk/eg for Trwyn Talfarach 215257, I'd type SH2125 in the search images box, then click on the os map for a pop up that zooms down to county records level for some places..
download a free app called Maverick