If you're interested in purchasing the Rocksmith 2014 PS3 DLC PKG, here are some recommendations:
Official DLC for PS3 is becoming increasingly difficult to access as Ubisoft has begun delisting content due to expiring 10-year licenses. While some users report still being able to purchase certain tracks through the PlayStation Store on the PS3 console, many "PKG" (package file) discussions now center on using a modded console to install Custom DLC (CDLC) or backups of delisted content. Official vs. Custom DLC on PS3 CustomsForge - Rocksmith 2014 Remastered CDLC
If you are trying to add community-made songs (CDLC), the process is different: File Format : CDLC for PS3 typically ends in _ps3.psarc.edat
