https://drive.google.com/file/d/1UvE...ew?usp=sharing
With the missing page added back in.
The Center for Computing History has those letters (Product 73300 and 104831) and it is the basis of my assertion that we need to get as far a NIBL and a proper keyboard on the KB Expansion connector... but, as Sirius says that is a great addition to your collection.