You can use this program to unpack any pbp file, make pbp files, and unpack param.sfo and make param.sfo files.
Here is the link to the pbp/sfo unpacker and packer
Ive used it, and made some of my own eboots, the program works. Its pretty cool too and easy to use. You can edit almost anything in a pbp or .sfo
If this isnt old, I sure hope it helps...