They look like a very similar design to those made by a German guy for the legsworld.de site. If you have a look in the previews, there are a few examples of his attempts to make steel shoes with very narrow heels.
August 16th 2005, October 4th 2005 and 7th November 2006 previews specificially. (Legsworld is an adult website, contains nudity and is therefore not for minors to view, however).
This was his second attempt.
http://img527.imageshack.us/img527/6...0513238jv6.jpg