One important thing I forgot to mention. The reason why the serial number starts with
ES is because it stands for "exposed sample".
The black square with IIIS is typically added into the note, which in this case makes it "exposed" to show how the private key is protected. This is also why you can see that it's overlayed on the design.
Essentially, these are prototypes that were given to Batesresearch with full permission to either auction, hold on to or destroy. All the proceeds from the ones gifted will remain with him, and I'm glad that we can all support his great cause.