These comprise four volumes entitled "London Brighton & South Coast Railway: Signal Boxes in 1920-1922". Some later additions have been added to correct or amplify the earlier sources. A fifth volume similarly covers the Isle of Wight prepared from information collected by the author over a period of more than thirty years; these signal box diagrams include locking tables.
A combined index to the Wagstaff series is available. The index is in Adobe Acrobat® (PDF) format. If you haven't already obtained it, the Acrobat® Reader program can be downloaded from here.