This is a rare instrument indeed, a brass cased water level/tank indicator. It looks to be manufactured by W.R.Sykes & Co and is excellent ex box working condition. One can see that where is was on the instrument shelf it was difficult for the signalmen to be able to polish it all over! Gainsborough Lea Road (Gainsboro) Signal Box was on the Great Northern & Great Eastern Joint Railway`s line between March and Doncaster. Plenty of information and pictures on the net and I believe you can just make this indicator out!
