Pajero Harmonic balancer and worn crank end.

There is an old (3.0V6) Pajero here on the property which I have been told I can use if I can get it going. It has a few things which need fixing, but the only one I am unsure of is the harmonic balancer. Here's the story...
The harmonic balancer kept falling off, so they bought a new one and it does the same. So today I inspected it and the end of the crank is worn. Now, I could do the old bush trick and weld the fucker on, but to me, that's a very final solution which precludes it ever being fixed properly in my eyes. What I wanted to ask, is if you think it might be possible to build up the crank end with some weld and then machine/grind it down so the balancer stays on? My concern, is that the crank may not like the heat from the welder. I don't want to have to strip the motor and pull out the crank to do it, as then I may as well buy a new/2nd hand crank.
Thoughts?
The harmonic balancer kept falling off, so they bought a new one and it does the same. So today I inspected it and the end of the crank is worn. Now, I could do the old bush trick and weld the fucker on, but to me, that's a very final solution which precludes it ever being fixed properly in my eyes. What I wanted to ask, is if you think it might be possible to build up the crank end with some weld and then machine/grind it down so the balancer stays on? My concern, is that the crank may not like the heat from the welder. I don't want to have to strip the motor and pull out the crank to do it, as then I may as well buy a new/2nd hand crank.
Thoughts?