H.S. Crocker was a large stationer in the SF area. They probably ordered them for a customer. Here's a 1922 magazine article that mentions them. They were still in the office supply business when I worked in the Bay Area 40 years ago.

https://books.google.com/books?id=yhAdAQAAMAAJ&pg=RA16-PA24&dq=hs+crocker+office&hl=en&sa=X&ved=0ahUKEwigg5fjmpTKAhUJ1GMKHRvbA5AQ6AEIKzAA#v=onepage&q=hs%20crocker%20office&f=false