Assuming you have PKGi v1.40 or higher installed on your PS3:
The true ending of the game was paid DLC. The "new" PKGi list includes a merged version (Base game + Part IV).
As of April 2026, the PKGi application for PlayStation 3 continues to serve as the primary homebrew tool for downloading and installing
Recent updates to the PKGi game list (via the official TSV files) have added: