Duke University library history sheds no light on the acquisition of the modest collection of comedias sueltas. These 100+ plays were most likely acquired over some decades and by various means and catalogued by different generations of librarians. It is likely that the bound volumes were originally bound by the previous owners, booksellers, or perhaps library.
Mack Zalin of our team was employed at Duke at the time and he personally photographed the sueltas, converted and remediated the records for uploading to our database. Nothing beats having an inside man!