Roslyn Rensch’s second book, “The Harp, Its History, Technique, and Repertoire”, contains a fairly comprehensive list of recordings (at least in the US) up to the time of its publication.
I have seen a list of 78 recordings. There was a partial list in the American Harp Journal. You can search the Library of Congress or New York Public Library. Salzedo made recordings with Trio de Lutece, very interesting. Ada Sassoli made at least one. But collectors are loath to part with them.