This is my transformation of a Mini Skewb. I started making it in 2009 shortly after my Unique 2 but got bored and moved on to other puzzles. I only finished it off in March 2012.
It's similar to my Golden Cube in several ways. Obviously there is the colouring and Skewb core. Also there is a 'corner' that has no obvious correct orientation. This leads to parity problems. In addition, when solved the puzzle is actually a part turn away from a completed move. So, as with my Golden Cube this part turn must always be made (in either direction) before scrambling or at the end of a solve.
To be honest I never really wanted it to be gold but having tried some other options it was by far the best looking. Colouring sides differently makes the puzzle much easier so for my third unique puzzle this was never going to be an option.
The name comes from the fact that it's a one off puzzle. There are no moulds so exactly reproducing it would be very difficult and because of it's mostly random shape it's highly unlikely anyone would have or will make the same thing by chance.