What is it?

Those are the "side brackets" that are soldered onto the side of a radiator core in order to mount it to the radiator support.

It looks like somebody melted the solder and saved them hoping they could re-solder them to a different core so they could use it in the car they had.....ie: attached to a 19" or 20" core to be used with a radiator support that had a 26" opening....
Thanks! I see it now....