940 The nut welded to the body that the rear spring perch nut goes through has broken off

I was going to tighten the bolt that goes through the welded nut in the body for the spring perch but it started to spin then I noticed that the weld had let go which held it in place. I removed it and wonder how have you others solved it? Just re-weld it back?

TLDR; Cant tighten rear spring perch because welded nut has broken off, help

Unless you can hold it with something as you tighten it rewelding it is probably your best bet.

Any chance of drilling through the beam and using a long threaded rod?

I just repaired a fixed nut on different car by first welding it to a thick washer, then I made a hole big enough for the nut to go in the beam. Then I welded the washer to the beam.