Run into the same thing on a jeep axle changing axle bearings on a Ford 9" where they (PO) cut the race off with a super thin grinding disc, maybe a 1/16 wide but it was quite deep.
Fixed it by welding it up and filing it down by hand w/a file and buffed it with Emory cloth 320grit.
Set the welder on as low of amperage as it'd go, just touched it a few times like spot welding just Enuff to fill the hole and filed it down by hand.
Don't want goobers or heat on it just wanna fill the holes.
Worked better than i could hv ever hoped for. Just take your time, you're not in a hurry and use the utmost care and finesse, you got this.