Have you successfully created a custom IRD for a modified MGS4 backup? Share your experience in the PS3 homebrew forums – but remember to respect copyright and distribution rules.
Verification: Use PS3 ISO Rebuilder to load your folder of files and the IRD. The software will highlight any missing or modified files.
In the context of MGS4, the game was unique because it was a dual-layered 50GB Blu-ray disc filled to the brim with data. When users dumped their own discs, the resulting ISO was massive and heavily encrypted.