[Flying Hamster]

Replacement locks for tool boxes are available at many box stores. They may not be "Correct" but they will work. Look for one with the same depth as the original lock. See if the "Arm" that interferes with the latch will bolt on. If not, bend the one that comes with the new lock into the same configuration. It is important that the latch be locked when the box is closed and the truck is in motion. The latch WILL bounce open without the physical interference. We had boxes like this in trucks where i worked many years ago and replaced quite a few locks this way.
Obviously, we didn't care about "Originality" as these were working trucks.