Broken missile launcher
This weapon can not be equipped and is not repairable with weapon repair kits. It has no value. It has full weight. It can, however, be used to repair working weapons of the same type. This seems to be its only use; there are no other known uses for broken weapons. Some broken weapons will not even let you pick up the item and place it in your inventory. You can in fact mod the broken missile launcher, AND you can repair it, quite easily. You can mod the broken missile launcher with a guidance system. You can repair it with any other missile launcher in the Mojave.
For some odd reason, you will occasionally see enemies armed with this weapon who are able to use it on you, despite the rules of the game. It can be theorized that it is just near to broken when you stumble across these foes, and then the weapon quickly deteriorates on the sight of you, possibly out of fear.