Why not london victoria/charring cross/London bridge to brighton? Or maybe some kent services out of victoria or st pancras?
I would love to see the old London St Pancras Midland Line, with Luton, Bedford, Wellingborough and my Home town Kettering along with all the rest St Albans etc to make an appearance.
Would be super cool man honestly, im all for the variety like what ts get on pc. Driving 222s outs of st pancras and seeing eurostars and 395(hitatchis) on the other side would be a dream!
