I am new to Roots - and am also very interested in Holms, Glengavel Farm. The 1841 census and Craigs referred to - included Ann (Hamilton)Wingfield, my family ancestor who was born Strathaven 1795, emigrated to Canada. I feel sure she is related to Mary Craig, not sure just how, but Mary's maiden name was Hamilton, right?
The website I'd like to pass on is Geograph UK for terrific maps; you can see Holms below Drumclog, the Glengavel Water & Reservoir, with photos. The photographer is Gordon Brown, with a link to him - I've 'talked to him' - very helpful. Good luck.