Lemax made a 10" tall one. There is one on ebay.

The photo below shows the blade of one windmill and another surrounded by flowers. They are both Department 56 products made in porcelain. Please click on photo to get a larger view.

Plasticville Windmill With Farm Machinery

Somewhere, I have a ceramic "holiday display" one from some maker, that has metal

blades that freely spin...it looks about as realistic as that Lionel one, but could be

modified to operate (you can blow on it and spin the blades, for whatever that's worth)

The Plasticville windmill can be made to rotate useing an aquarium air pump.

Good project idea!!!

I've got a pair of very small bevel gears that have been kicking around the motor/drive parts box for some time.  Seems like they'd be just the thing for converting a free-spinner to a motor driven (maybe with a bit of geared speed reduction underneath) vane shaft.

In fact, if I don't bother oiling it, I might even get an appropriate 'squeak-squeak-squeak sound effect from the "Rube" Goldberg results?  Nah, probably should see whether George @ ITT Products could help me out with a squeaky windmill sound module!

Now to find an appropriate guinea mill....

I have that same exact Windmill that operates. It works. The issue I have with it though is if you have to little of power say around 12 volts it turns and stops. But if I add a little more power around 14 to 15 it turns better, but looks to fast.