Unknown part help
My first thought was front rear spring hanger,
By the large diameter pink (red?) paint circles around the bolt holes on the right, I suspect they fit inside something that has larger diameter holes on it to allow for adjustment.
The one on the right looks like only 3 of the 4 holes has the paint around the holes, does the other have the same markings but mirror image?
If so, you are looking something with 3 holes that bolts to something else and requires adjustment.
Best Sherlock Holmes impersonation I can come up with