I do not not know PSP very well, so this answer will be very restrictive/limited. I do know eboot is used on PSP/PSvita/PS3 as well, but in other fileformats and signing (at least on PS3 they are AES encrypted and ECDSA signed, on PSP they seemed to use Kirk keys for encryption, not sure about signing - afaik on PSvita they also use AES encryption and ECDSA signing just as on PS3).
If you have both originals, and both output files, then you can diff them with HxD/winhex etc. or look them over what code they exactly fix with IDA.
So, other than reposting a bunch of random, unrelated stuff from other people, what do you have to contribute?