Hey, check out what I found. In my search for all things steampunk, I came a cross a guy who has converted some old Tamiya tanks to be steam powered. The only electronics according to him are the reciever and some servos for controlling the steam engine.
He also has some walkers and other neat doo-hickys. Not exactly tanks since they have no gun, but I thought it might interest people here.
http://www.crabfu.com/steamtoys/
Just click on a picture and it'll give you more detail, some have videos.

Anyone know where i could get one of these clutch driven Tamiya chassis he talks about? They seem to be an older model and not produced anymore. How much can I expect to pay for it?