Jusupov released his 100% completion fix for the PC release many, many years ago.  For those who don't know, this game has a major flaw - 100% completion is impossible despite Mercenary Mode challenging you to reach it!  One of the final two missions doesn't award its weapon and vehicle parts, and one water tower is missing from the game world.  His mod addressed this by adding a custom location with these missing requirements.

However, about a year or two ago, the PS3 release became fully playable on the RPCS3 emulator, and I discovered that it accepted files from a dropzone folder like PC, however most mods would have to be further modified, as the PS3 uses the Big Endian byte order, while PC uses Little Endian, and strange things happen if you try and load one in place of the other.  It took a lot of work, however after over a year's worth of experimentation, I finally backported the mod to PS3.

Simply create a dropzone folder wherever your EBOOT.BIN is, whether it's in the digital copy's directory or on your extracted game disc, then extract this .zip into it.  For the American PSN digital release, this would be:

dev_hdd0\game\NPUB30606\USRDIR\dropzone

Once ingame, head to the same location as before, X:18111,Y:15326 when viewing the map in the PDA, and the missing requirements will be there.  I've confirmed it to work on RPCS3, however I haven't done much testing on a real modded PS3 due to not having a working one, but it should be just as functional there.