Many thanks for all your comments.
This was all scratchbuilt apart from some small bits motor, wheels, buffers etc.
It runs ok but a little loud but might improve if it ever gets run in.
That looks better, the weathering on the real thing was random with varied marks.
Look very closely at pictures of the real thing, but they are great, it's up to you how far you want to go.
The depot looks amazing, what is it made from?
Have a look at High level gears they do a gearbox to one axle and it would not
take up too much room. Most of it would be under the floor level so just the small
motor on top which could be covered with a small box.