Good afternoon Jon, I am an exiled Bury Lad, and I travelled on the "Bouncing Hummers" lots & lots of times, nice application of the GMT livery, as others have said these units also appeared in rail blue & blue grey before the GMPTE livery appeared, are you going to be modelling the lit mercury bulb in the centre windows, please find below a couple of great 17 minute videos by signalman John. C. Earwicker, here it shows some great footage of the last days of this line under BR ownership, including the units being dragged off for scrap, and engineers trains etc.
Happy viewing.
Craig.