THE CLINCHER....
The microcode was written as numbers on the horizontal left-hand edge of the book cover and across the top edge as highlighted. I used a combination of a forensic image analysis tool and UV lighting to reveal the concealed code. The layout/format on the code on the left edge is very similar to that used in the design of the HAY banknotes. You'll find a link in the 'RELATED POSTS section below this post....
THE GRAPES....
Here you can see the numbers written through the grapes on the title page of the Verse 70 inscription version, Boxall copy of the Rubaiyat. I believe that this example can be enhanced and will post that when I have it.