Hi Paul,
Looking good, I agree that you're going to have to have long legs top operate that layout.
On another note, the ends of your baseboard where the track is, have you thought about securing the rail with something, like maybe a brass pin fixed into the wood and up through the sleeper?
The track is prone to being caught, no matter how careful and good the intentions, and it will just wreck all your hard work.
Chris (Too Many Spams) on here has solved the baseboard end problems with one of the most unique and well hidden ideas I've seen. Have a look a bit back through his Pencarrow thread here: http://www.rmweb.co.uk/community/index.php?/topic/69736-pencarrow-pg255-wagons-walls-bufferstops-and-pain/
Just a thought
Jinty