Signalling interest, a small bundle to include:-The Institution Of Railway Signal Engineers Booklets , qty 10, nos 1, 4 - 9, 11 - 1: Railway Signalling Symbols Parts 1 (1937) and 2 (1954): Railway Signalling & Communications second edition 1946: British Railway Track second reprint 1950: GWR Official 'Track Topics': couple of wiring diagrams including one of Haverfordwest and a couple of other books.