For the Bea-Dawe route, I'd like the early days of nationalization, before the equipment was relettered to BR, as that would mean that I could run LNER-lettered (i.e. Mallard or Flying Scotsman) locomotives on what previously only seen GWR equipment. Or I could go model post-1955 and feature their unique diesel-hydraulics. Given that Class 55 Deltics appear on the Appen route, I think that Appen is part of British Rail's Eastern Division, which is Ex-LNER. I'd take the steam era for Appen, so that I can run Mallard or Flying Scotsman on it.