When I think LEGO customization I think of minifigs, but there’s an amazing subset of train builders that go to a whole new level. Case in point, Carl Greatrix (bricktrix) has built this wonderful diesel locomotive from Birmingham Railway Carriage and Wagon Company (BRCW):
Not only is the build stunning, but the sticker work, lighting system and built in DCC is nothing short of brilliant. If you aren’t squeamish – Carl has posted a picture of the inside guts of his Class 27 train.