As I was slowly going mad with the construction of Ratio Signal kits for my layout, a thought crossed my mind. Am I correct in thinking that Oil?  GWR Signal Lamps were maintained by a lamp-man, whose job was to clean the spectacles, trim the wicks and top up the oil. If so, did these stalwarts have to walk miles of track to the next section? Presumably maintenance/topping up would have been done on a regular basis if the light was not to go out. How long would a lamp burn? I guess that some l