Triple post (sorry again..), but now Pieksämäki CTC tower has bases too:
I think that as in Iisalmi and Kokkola stations, asphalt and gravel base tiles are enough for this tower's base. IMHO these are better than it's original base.
EDIT: Equipment cabins (3 types) done, every base type (5 bases) with each five (one exception has six) options of placement.. Total 80 tiles
Have a graphic candy for your railyard and signals, and level crossings. I think that when equipment containers and these are coded, railset and roadset-integrated level crossing containers can be removed, since then, player can choose any type from available ones if (s)he wants.
EDIT2: I'm currently working on base tiles extended to templates (1x1 to 3x3), and sand base needs to be redone from it's borders, because it gives irritating grid. All others are working quite nicely. Grass has little borders too, but they aren't not so irritating, so it's not so bad. Also, some grass tiles had 1 px cut off by accident of their right side-> Done. I'll work all these issues out.
EDIT3: Is this piece of sand ok, does it fit to TTD-Windows palettes? I'm not entirely sure about that, because i edited this with Gimp and had TTD Win palette selected, but cannot be sure about it. I used healing tool to fix those borders. If it is, i'll replace current sand with this one. After that, i'll replace all already "sanded" stuff with this. Quite a work, but if i left those unchanged, it wouldn't look so pretty. Luckily, there's templates available for everything, so it's not so difficult.