Rear Striker Lost a Bolt

[jayis]

Hey everyone, I bought a 2008 Yaris manual with 126k miles a few weeks ago. The rear hatch striker is completely loose. The striker is the name for the thing that the latch grabs when the hatch closes. When I took everything apart, the right bolt for the striker was completely missing. I unscrewed the remaining bolt and noticed that the thing the striker is supposed to screw into looks like it has a section snapped off. I can probably replace them with some other nuts and bolts but I like to try and keep original parts if possible. I am considering just going to a junk yard and taking the rear striker apart and taking whatever the striker bolts screw into. I searched all over for a part number for what I am looking for and couldn't find it. Any recommendations?

Attached is an image of the pieces.