Assuming the POs were like most people if something goes wrong injector wise they seem to just replace the bad ones with remans or new. Everyone is different, but I would assume some or all could be original.

Jim @ Rosewood diesel shop is the man for injectors IMHO.
He is a sponsor of our forum and at the top right of the thread above the "Rate Thread" option and below the "log out" option you will see a link you can click.