A very nice touch i noticed is the scrap piece of rail on the sleeper ends along side the class 22. You've perfectly accented the different rust colour where its been sat in the chairs!
Never seen that modelled before with regards to the colouring, most impressive.
Sometimes its the little things that make a big difference to realism.
One tip I picked up years ago, have you tried an HB pencil on buffer heads to replicate grease??