As some on the forum will be aware, British Rail still lives on to some degree. BRB (Residuary) Ltd. is responsible for the structures associated with closed lines and disposing of property which is no longer required for rail purposes. You might be interested in a little tool I've thrown together to search by postcode for nearby BRB (Residuary) Ltd. property. You'll find it on my website at http://www.adambrookes.co.uk/brbr/property. Any comments/problems/suggestions etc then please let me know. Note that the locations given are approximate because they are only available as six figure grid references which aren't brilliantly precise. Therefore the relevant structure will be nearby the marker, not necessarily directly under it.