NSW 24m, 18m, 8m, 12m Arched Subway Roofing Link
https://www.sendspace.com/file/5tlgxc
Rememeber it can only be seen from underside of roof
Regards steve
Thanks Steve, They look great. You're a champion and I really appreciate it mate. I can make good use of all the roof sizes.
Here's a quick screenshot which I've done with the 24m width on a very basic 'Museum' station before it was tiled. The roof still alows good lighting.

Cheers,
Roy3b3