nostr:npub19lt4284mghqxekzm6n5njxurnxrxhqhrva2leusdsuu5ja5jeycq66qfjk, for old books the standard OCR models of Tesseract (which is used by ocrmypdf) are often not sufficient. Look here for better models: https://github.com/UB-Mannheim/tesseract/wiki#tesseract-models-for-historic-prints.