If the PDF is no longer available digitally from the manufacturer, physical copies are often found on sites like eBay or Etsy, where sellers sometimes provide digital scans of vintage patterns.

This is the most comprehensive community database for fiber arts. You can search for the "bo064150" code to see if the patterns are listed and where they can be officially purchased or downloaded.

Check the Phildar website under their "Modèles" (Patterns) or "Catalogues" section. They often sell digital versions of their archives.