2017 will be a bit year of change for Knell Lane, not only will the layout be replaced by a brand new one (as mentioned elsewhere) i'm also going to change the era the layout operates in. Currently the era is about 1968-72 but this will change to 1968-92. This will encompass most of the British Rail era and will open up a lot more possibilities for new stock and liveries.
Now of course this will not be very "authentic" but Knell Lane is supposed to be fun not a rivet counter paradise. Anyway i bet you can't wait to see the Class 22 haul a train of coaches in Regional Railways livery!