If you've watched the latest BRM DVD then in the Ruston Quays chapter, there is a little footage showing the smoking chimney looking from the back of the layout. As you can see from the screen grab above, this highlights that the smaller warehouse didn't have a back to it.
From normal viewing angles, this doesn't matter but if I think like this, I'd not have bothered with the point rodding or the backs of the brick parapets. I have a feeling that there are some interesting angles for photographs to be taken from back here so a bit of detail is required.
Which is why, before I fixed the building in position, I've added some back wall brickwork to fill in the gap. I should have done this as part of the construction originally but the bodging doesn't seem to look too bad.
Next time you see the layout, ask nicely and you can look around the back to see my efforts!