Looks like it was a Die Proof of 20,000 that was never used. Copy the entire URL and paste it into a browser and it links to a PDF from Steiner. For some reason it only takes the first part in the post
https://www.google.com/url?sa=t&rct...ECBAQAQ&url=https://evols.library.manoa.hawaii.edu/bitstream/10524/12239/1/HJH43_57-80.pdf&usg=AOvVaw0eM5zq-Xjo7FHDtk9PF6Xu
I don't know if is real, as there were lots of fakes.