Download MLB 08: The Show

These Redump format files are in the ISO, which can be read by a real PS3 when decrypted. The discs can be extracted into the JB folder format for use with RPCS3.
Note that these discs are encrypted. They must be decrypted using a program such as PS3DEC, and the Disc Keys found here. The decrypted disc can be played in a modified PS3, or the files can be extracted in RPCS3.
You can try searching our two PS3 PSN and PS3 Redump directories for games you didn’t find on the web. Good luck.