I printed out the latest track plan at full scale this evening and laid it out on the living room floor to have a look at it properly. Almost immediately it was obvious that it didn't work for several reasons so I went back to the drawing board, and here's the revised (well ok, totally new!) plan...
The platform would be at the back right, the main goods yard to the front, with a (optional) short siding off the platform approach road - a loading dock (or former site of) maybe?
I've taken out the loop return; moving this 'off-stage' means there's a bit more real-estate available for the goods yard.
All but one of the turnouts are C8, which is generous for a layout of this size, but I think it'll look a lot better than trying to use tight radii. I've also introduced a gentle curve to the tracks on the left baseboard, resulting in the platform being at a slight angle to the baseboard edges, to provide a little relief from the otherwise very linear plan.