Ok so here's the more or less finished article. Just need to do some finishing off on the base. Quite happy with it in the end. It doesn't come across in the pictures but the railtrack is done with humbrol metalcote which can be buffed to a metalic shine when dry. Really worked well on the shiny part of the track in contrast to the rust effect I went for underneath. I got the tip from the Michigan Toy Soldier videos on youtube.
I hope these photos upload correctly for what they're worth! Cheers.