Anyhow, five years later....
First off, I need to apologize to JQL for providing some incorrect information in my response to his question 10 years ago.

In my arrogance (and ignorance) I told him that the robot never existed outside of the lab. Well, of course that was wrong. It did exist in the upper city towards the end of the movie. When the False Maria was being burned on the bonfire she briefly transforms back into the robot. My bad 

As far as my Maschinenmensch, every now and then I wake her up and make some tweeks here and there. Sometimes they work, sometimes not. But I feel that it is gradually improving, maybe not a whole lot but it's slowly getting there. She is my favorite project.

And now, speaking of that bonfire, during my extensive research for the making of my Metropolis robot I came across a number of theories as to what ultimately happened to Walter Schulze-Mittendorff's amazing creation, from being destroyed in the war (huh?) to being hidden away in someone's private collection somewhere, even suggestions that WSM had created two of the robots, with one being destroyed in the bonfire and the other still existing somewhere, and everything in between.
But I subscribe to my own theory, that it was indeed destroyed during the big bonfire scene at the end of the movie, but not because it was destroyed in the actual fire (there is no photographic proof of that happening), but that it was for all intents and purposes destroyed while it was being prepared for the bonfire scene (for which there is photographic proof).
The suit was never designed to stand on it's own, only to be worn by Brigitte Helm. The many individual parts were molded onto a full body cast of Ms. Helm (can you imagine what that cast would be worth if it was somehow found today?), with thin layers of a very early version of Plastic Wood being applied to Hessian, an early version of burlap. Without her to support it they apparently had great difficulty getting it's parts and pieces to stay in position and in their not-so-subtle attempts to get everything to stay where they needed to be they apparently tightened the straps to the point where they broke through the robot, causing extensive damage. Further major damage was caused to the shoulders and arms while trying to get the arms bent out and back (the shoulders of the robot were sculpted as part of the body, and could not be moved).

For me the real question is why Fritz Lang, who's demand for perfection in absolutely every detail to assure that his vision of Metropolis was was not compromised is well known and documented, would allow such an obviously tattered and broken and much-less-than-perfect, to say the least, version of the robot to become part of his masterpiece at all. It is totally out of character for him.
Some other observations, for what they're worth

Well, just thought I would see if I remembered how to post stuff here. Boy, has this forum changed, hardly recognized it!! If it's not too much trouble I'd appreciate it if you could change it back to the way it was back in the good old days.
Hope everyone's holidays are going well!