With thanks to H-Hist-bibl for this reference.
The Internet Archive Scholar provides a search tool that retrieves papers and similar OA materials that have been collected by the Internet Archive including pre-publication papers and digitized microfilms of older material.
Below is an excerpt from the webpage for the project followed by a link to the page:
"IA Scholar is a simple, access-oriented interface to content identified across several Internet Archive collections, including web archives, archive.org files, and digitized print materials. The full text of articles is searchable for users that are hunting for particular phrases or keywords. This complements our existing full-text search index of millions of digitized books and other documents on archive.org.
The service builds on Fatcat, an open catalog we have developed to identify at-risk and web-published open scholarly outputs that can benefit from long-term preservation, additional metadata, and perpetual access. Fatcat includes resources that may be useful to librarians and archivists, such as bulk metadata dumps, a read/write API, command-line tool, and file-level archival metadata. If you are interested in collaborating with us, or are a researcher interested in text analysis applications, we have a public chat channel or can be contacted by email at firstname.lastname@example.org."