I looked at the Bevo Mill way back in July of 2013, but over the weekend the interior was open due to a special event. I have been to the restaurant many times over the years, back in the day, and a few times since it opened under new ownership.
What was most exciting is that the tower of the windmill was open, and the renovations of what had been an apartment (images of the rooms pre-renovation are floating around out there on the internet) are complete.
The photos above and below are the rooms on the first level above the restaurant.
The windmill blades, which in a working mill would be wrapped in canvas, rotate by as you look out the windows.
You can see how the tower tapers up on the next floor up.
Finally, on the top floor, the giant axle that operates the windmill is easily viewed.
The motor is relatively small, but they usually are! I was allowed to view the motor that operates the clock at Union Station is about the size of a lunchbox.