I've just acquired a second hand book on the Southern Electric which includes a photograph of a Derby/Sulzer diesel (later class 24) hauling the 9.10 am Hitchin - Brighton train near Honor Oak Park on a Sunday in June 1962. I had no idea such a service existed then. Was it just a summer weekend service and what route would it have taken through London? The Snow Hill tunnel remained in use for goods traffic until the end of the 1960s so was this the route taken, via Blackfriars and london Bridge, or did the train take the East London line, reversing at Liverpool Street?