I’d say that’s a pretty easy fix. The only thing that would concern me is how many other holes like that are close to showing their ugly self. I’m sure a good radiator shop could pressure test and fix you up .
Steven
Before you even attempt it I would look the rest of the rad over very close. When you peer down the neck do you see any blockage in the fins? If it is a 20" wide rad it might be a good time to upgrade to a 24" rad.
I gotta tell this story, circa 1975, and I had a 65 Mustang. A small hole, just like you showed, appeared in my radiator. My father had just taken up welding and said he could fix this right up. He fires up his Oxy-acetylene torch, lowers his mask, and before you know it, I had a silver-dollar sized hole in my radiator. Well, he did up paying for a replacement radiator.