Version B7a has arrived. Changes include:
- reworked skybox
- fixed train not destroying engineer buildings
- fixed multiple clipping errors
- added more metal near tracks
- added windows to spawns
Download:
http://dl.dropbox.com/u/9180221/TF2/koth_namicott_b7a.bsp.bz2
Unfortunatelly the doors must stay, because otherwise there will be 6500 unit sightline at all times and that is rather unfun for non-snipers

I tried to block out a wider layout, but ended up with 6000 unit sightline between 2 areas, so they can only be enlarged towards spawns - stretched longer, not wider. I think I will try that, but not anytime soon as the map has worked it's way onto some servers and I don't want them to have to update every 2 weeks.
The last night test I had went well, except for the fact that framerate is now at the point where adding any more detail will create fps drops at the ends of the track. Therefore I hereby make a note to myself to look more into optimization in next version. Widening the areas while keeping door chokes the same might help I guess by having some detail moved away from the track.