Many users report dead links in the comment section of the specific post. The uploader sometimes provides "mirror" links or re-uploads requested parts there.

Providing that name will help me find an active mirror or an alternative source for you. Diabolus In Musica: Paul Badura-Skoda plays Schubert

If you have the other parts, ensure you are using the latest version of WinRAR or 7-Zip to avoid "Unexpected end of archive" errors, which sometimes occur if a part is just slightly corrupted rather than missing.