After some thought about the mockup I did, and as a result of some discussion at the clubrooms as a result I have two more ideas to write out. Both these ideas base the layout like idea 4. But the change is the triangle. Looking at the mockup, if used to scale the radius would be say 15ft. If we keep this roughly to scale we end up with an "L" shaped section, that once the track has included the BG triangle, means we can then revers direction with a 3ft radius curve back 180% to head to staging. the staging would be at the end of the layout, well some of it would be. The diagrams below do not show the length we would have, I would say we would get 15-20ft, which is as long as our present layout.
At this point the ideas split:
If we kept the elbow or boomerang part to have the Coal Sidings and Albury Bridge in proportion to each other, it would mean a longer layout, but with 90% of the modelled scene at the front, we could not have a lot of the layout hidden against a wall.
It also gives us space for more staging, or for longer thinner staging rather than having a big wide board.
In order to keep the size down the right curve from the coal siding to the Albury bridge now has a 180 degree curve. This puts scenery on 3 sides of our layout. It does not means we loose staging as we can have some staging behind the bridge side.
It does make for 3 sided viewing, but could be a negative thing if one side of the layout is placed agianst a wall or other layout.