I don't think the 1850 map is large enough to show the Cliftonville loop (Railway from Preston Park to Hove). I estimate that it is just to the left of the visible map, working out that the large crescent to the foot of the map is Adelaide Crescent.

At the top right of this map, just to the left of where Queens Park Road joins Elm Grove, there's a short spur-road shown. The end of this is "Scabes Castle". Does anyone know anything about this?

The map would show the Cliftonville loop but for two facts. The loop leaves the London line at Preston Village to join the West coast line at Wilburry Villas. It would nearly all be on this map, but the picture of the manor house obscures it. More crucially, the loop was not completed until 1879.
The station shown on the West coast line incidentally is the original Hove / Holland Road station which was closed in 1880 and not the Cliftonville / Hove station we know today.

Scab's Castle Farm is shown on the Borough Surveyors map of Oct 1864 relating to the "Report upon the Tanantry Down Roads and Race Ground" I have a copy of the report with all the maps. Unfortunately although Scab's Castle Farm is shown on the map (where Tanantry Down Road is today) it is mentioned only once and very briefly in the report by the surveyor Richard Edwards dated October 6th 1864. I'm going to scan the map and the applicable section of the report, soon.

It would be really helpful if the 1850 map was much larger. May be the Brighton History Centre won't allow it. If they will could a larger image be put on line?