The only person who would know is feng, as you can see in one of the pictures. He sold one last set in classifieds which I missed out on; he mentioned to me at the time that he would double check inventory to see if he had a final set but never got back to me, so I assume he indeed sold the last one.
The person who beat me to the punch on the set put in them in the classifieds not long after, and I was the person who bought them.
I am still fairly new here overall, so I have no idea how many were actually produced, but I think you'll be hard pressed to find any.