I had a quick look around and I haven't been able to find much.
I am want is small scale buildings, roads, railways, general cityscape and the surrounding farmland.

But there is catch, I want it Steampunk themed.
I want my Dystopian Wars land-ships rolling down cobblestone streets while my Sky-fortress rains death on the city's defenders.

For Steampunk themed check out and its accompanying
The , and work well for Steampunk, as do , , and .
provides generic (uncivilised) outdoors terrain, and there are some kitbashes that link Forests tiles with Himmelveil Streets.

If you need them at a smaller scale, shrink them before or during printing (one of the beauties of print your own terrain).

Railways are yet to arrive - we've been asking for those sometime; hopefully they're somewhere on WWG's to-do list. Farmlands/prairies are a requested add-on for the newly introduced DeadFall series of sets.

Of significant interest to steampunk fans is the idea of a steampunk airship which placed 2nd in a vote for possible future sets earlier in the year. No news about that yet or even whether it has made the cut for actual development, but we keep hoping.

I have some of those sets already and they are great for 28mm scale RPGs and wargaming.

I would love a set made up specifically for the 1:1200 scale Dystopian wars something like the terrain links sets, with each tile bring a city block as to make a interchangeable battle mat.
Add some tiny houses & huge factories to capture/destroy it would make for an epic battlefield.

They're not steampunk, but you might find some ideas and help in these threads: and