What a great find, John. I know the good feeling you are having.
About 15 years ago, I bought a brown paper bag full of chips for
$150. They were from an antique dealer from Middletown, OH, who
got them from a former employee of US Playing Card. I kept about
200 different ones and have given away and traded away the extras
over the years. I have been waiting for more bags to show up.
Looks like you found one--in the shape of a book. I, too, have a
salesman's USPC sample book and store sample board, but they are
all poker chips, engraved, embossed & die-cut inlaid--not great
personal order chips like the ones you just found. Envy, Envy, Envy!!!