This is really great! I only had a very quick look at it, and I noted that you, besides excellent graphics, also heavily have modified the menues. I must say I really like the approach you have taken, especially when taken into consideration the potentially many new extra signals that "Extended" has brought with it. Lookig forward to playing a map with it!
You should talk with james, and make the pakset available via the nightly download. Then you dont have to do releases as such (you still could announce whenever you make changes), and you make sure that every player always have the latest version of both pakset and executer. It would also spread the pakset out to basicly all players currently engaged in Simutrans Extended automatically.