That pin, I thought, was always a weak design. You can weld it back together, but it has to be heat treated afterwards. On these, I annealed, then quenched them, and last, drew them to spring hardness, and they performed all right, but don't draw one past this, or it will be too soft. Draw it less, and it can break easier. Also, you have to watch the length when grinding and clamping to weld.
If you can have one machined cheap, go that route.