Thanks for the feedback. There appears to be nothing disused about the airfield, despite its sometimes poor condition. There is an active entry in the Pooley's guide for it which mentions that light aircraft are accepted at the pilot's own risk, strictly by prior permission.

Having had to make a precautionary landing in a C42 Microlight at Wigtown a few days ago due to unfavourable weather across to Northern Ireland (VFR), I would recommend that you mark this as a disused Airfield and not suitable for use. In our case due to encroaching mist from the west and failing light, we had to land there, however, we overflew at low level and selected the best part of the small tracks that are still usable and managed to stop fairly quickly. Take-off required careful walking of the small usable area and marking out imperfections for the take off run. There was literally just over 100m of usable track.