Here's the set up: bought a load of books this morning, a gentlemen had dropped them off yesterday when I wasn't in the store. Looked through them, gave him a call with an offer, he said yes and that he'd be down later on to pick up the cash.
As I was looking through, I found this in one of the books:
The bookmarks are a small photo of a man and boy with the label "Chic" as well as a agreement card from a bank regarding a Second Liberty Loan, which I discovered were developed around 1920 or so, according to The New York Times.
The book is "Bringing in Sheaves" by A.B. Earle, published by James H. Earle, Boston, 1869.
When the gentlemen comes in later, I'll see if he can fill in any details about today's find, and see if he'd like them back. I'll update later on today.