I have been poking about in the files for KotOR and recently tried checking the save files. I also found that every save-file is in either GFF or ERF file-format.
The save folders contains five files of the following format:
In the GFF format. Contains the global variables for quests and such things
In the GFF format. Contains more information about the different NPC's that join the group, such as which of them that are available to the players. It does not seem to contain any specific information such as skills.
In the GFF format. Seems to contain information about the save game such as name and the module the game was saved in.
In TGA format. It is the screenshot of the current game.
In ERF format (encapsulated resource file). It contains the following files:
All of them are in the GFF format and contains the NPC's that join the group and their different values. Contains skills, name, gender and much information.
In the GFF format. Contains the inventory of the party.
In the GFF format. Think that it contains how different groups of NPC's like the character.
There are many .sav-files, one for each planet. For example ebo_m12aa.sav if for the Ebon Hawk. These files are in ERF format. They are the area-save files, they contain the following files:
XXX.git (each have a name like the file that contains them)
XXX.are (same as above)
Those files seem to contain information about the area. Much of the information is somewhat cryptic but it is possible that it can be useful.
So far I have not been able to find the information about the PC, but I'm working on it.
It is quite possible to use ERFEdit to unpack everything and then use GFFEdit to change the information and then re-pack it.