We have given ourselves quite a large window for operating the modules in 1935-1666. This should allow a wide range of sock and includes a number of defined era's and potential stock options.
Billingshurst was electrified in around 1935 but the lines around Sussex to Midhurst, Littelhampton and Guildford were not so we would potenitally have had a mix of early electrics and steam to consider. A bigger challenges will be that we have selected DCC and N gauge which is going to significantly restrict our options unless they are scratchbult
The Horsham Shed (75D) Allocation for the period is quite well documented and supported by the Aslef site ( The Sussex Motive Power Depots) as well as semgonline.
The 1939 Allocation for Horsham included classes C2X, C3, D1, E1, E4, E5, E5X, K,
In N we have the C2 class coming in 2019
Looking at my preliminary EMU research I think the core units for the period were 4 COR's
Southern Region Liveries (SEMG)
From 1923 the newly formed Southern Railway adopted a passenger stock livery of "Maunsell (after the CME R.E.L Maunsell) Green" - a sage/olive green. Where lining was applied it was chrome orange with black edging. The ends (except those on EMUs), underframes and bogies were black. The ends of EMUs were green. Lettering and numerals, which were of a block sans serif font, was gold shaded black beneath and to the right. Coach roofs were white or mid grey (when new!!!).
From 1937 the Southern's new CME O.V.S. Bulleid introduced a striking new malachite green scheme, referenced it is said, to a length of spectacle cord in the CME's possession. Coaches did not have lining in this livery; ends, underframes and bogies were black. Lettering and numerals were block sans serif in golden yellow and black (golden yellow edged black 1937-1941 and then 1941-1948 golden yellow edged and shaded black below and beneath). Coach roofs were mid grey.
A good reference book covering this period, now sadly out of print, is "Railway Liveries - Southern Railway" by Brian Haresnape, published in 1982 and 1983 by Ian Allan, ISBN 0 7110 1203 2.
Come nationalisation in 1948 the Southern Region of British Railways, as all other regions, slowly adopted the new mainline coaching livery of carmine and cream, lined yellow and black with yellow lettering and numerals. This livery weathered badly, so it was later replaced by a stronger crimson and cream, lined and lettered similarly. Suburban coaches were just the carmine or crimson, some lined some unlined. Where this suburban livery applied on the Southern Region lining was not used. Southern EMUs remained green throughout this period.
From 1956 until the blue/grey era of the mid 1960s regional liveries were permitted, with the Southern Region being quick off the mark to revert to their beloved green, albeit a new darker richer shade (BR Southern Region green). Lettering and numerals remained yellow. Certainly new BR Mk1s were introduced in carmine/cream, and pictorial evidence proves both Maunsell and Bulleid coaching stock was repainted into the new British Railways colours. However, the carmine/cream and crimson/cream schemes were not as widespread throughout the Southern Region as other regions, because of the Southern's long held practice of re-varnishing as opposed to repainting coaches. (It is from this practice that the North American railroad slang of "varnish", referring to passenger cars, comes.) By this method the Southern region was able to hang on to its green coaching stock longer, and many coaches were not repainted, but merely re-varnished and re-lettered, until the Southern Region green livery was introduced in 1956.