I might haven't played the game but I've been "tracking" it down for 3 years now. I've watched thousands of videos, including route building videos and it is easy if you get it. I can build, I can work with signalling but I am not an expert in 3D modeling etc. I'd like to build a 1:1 map of the Greek Railway Network loginjet.net. I don't know if any expert in creating vehicles and wagons and buildings wants to cooperate. And note that DLC's are not free, usually, but I don't have a problem, I could work with someone but I don't want any money, I'll buy the game and that, just to work on this project.
I'd be very happy to travel to places not covered by TS yet. Unfortunately I'm not a modeller, but good luck with your project!