An interesting question for those who like to tinker with old guns.
In gunsmithing by Dunlap, he says he uses the 3.5% nickel-steel rod for most gun welding jobs. I don't think the weld is too hard so may be easier to re-shape amd fit, could building up the bites be an easier option ?. I'm not an expert on this so hope someone will come along with some info. There's very little written on subjects like this, if anyone can help I'm sure a lot of others will appreciate it.
Good luck.

Rust never sleeps !