Sadly the article this refers to that talks about the demise of catalog cards, https://www.smithsonianmag.com/smart-news/card-catalog-dead-..., has links to the company that printed cards, OCLC, that are also now dead - https://www.oclc.org/support/services/worldcat/documentation... At least the catalog cards would have given you better information than the 404 errors (which would have been live only 8 years ago).