I answered the same question in the "talk" section to someone else.....
Looks to me like you've got plenty of meat left on the stud to grind a bevel on the end, also on the end of a new stud and mig weld it on. If it were mine I sure would give it a try. If you were closer, I'd also give it a shot...what have you got to lose? Do you know any welders in your area that know what they are doing? As far as welding a repair stud on, this job only looks worse than it is. A good weld will be stronger than the stud itself!
Looks to me like you've got plenty of meat left on the stud to grind a bevel on the end, also on the end of a new stud and mig weld it on. If it were mine I sure would give it a try. If you were closer, I'd also give it a shot...what have you got to lose? Do you know any welders in your area that know what they are doing? As far as welding a repair stud on, this job only looks worse than it is. A good weld will be stronger than the stud itself!