Many - but in railway terms, all pre-BR buggeration, and preferably pre-Grouping...! GWR primarily, but shades of LNWR/Midland/LMS. (I'm modelling a GWR/LNWR - LMS Joint' line.). Ideally, model railways represent a real place at a specific period. The location has to fit the space available - tricky - but the period...? So much choice.... :-). 1890's - to about 1920 is my favourite.