Stopped by Rockslide today to take some pictures. They were assembling a set for a JK so I got to see the inner workings. As you can see, the mechanism is totally internal:
And the mechanism is outrageously beafy --that's 1/2" steel used for the step brackets and the sliders are 3/16":
And here is the shot of the underside:
Notice the optional light that turns on when the door is opened. The SMB versions mount differently, but as you can see, everything is very protected.
Steve is waiting for the machine shop to finish their bid, so we can determine the deposit.
Tom