Found this whist absent mindedly trawling Ebay - I believe they are genuinely hard to come by, so thought someone might be interested. Its a Tolhurst VOR coal fied loco.
http://www.ebay.co.uk/itm/SM32-Coal...266429?pt=Model_RR_Trains&hash=item3cc900203d
http://www.ebay.co.uk/itm/SM32-Coal...266429?pt=Model_RR_Trains&hash=item3cc900203d