If it were me, I would get some brass rod the diameter of the mid section of the stud, cut to length, ,then thread them to the same diameter, pitch, and length as the originals. Thread a nut down to the bottom of the shorter threaded section, and solder in place from the inside. You can make the reduced size portion on the end by chucking in a drill press and while spinning, use a hand file to reduce the diameter. You can also reduce the diameter of the soldered on nut the same way. Factory is better, but the home made path works well too. Drilling the cross hole is easy in a drill press too.
Mitch