RISC OSMap of G.W. SignalboxesRISC OS
http://www.svrsig.org/gwmap/GWMap.htm
Sxxxx numberSignal Box nameView on map squareOther information including SRS diagram number
S 163 Cholsey Map BX115
SU584860
SRS diagram P301
S 174 Wallingford Map BY117
SU601894
SRS diagram S792
Prices are shown here.