Messed up D Nuts for header attachment

[ModelAJim]

Guys this isn't my actual pic but the screws for the header broke and I had to drill a couple out . Well one got a broken bit and now the hole is offset. I ran a tap in it but it looks like crap. Functional but crappy. Has anyone ever drilled them out and welded plugs?

Or other ideas?? I can't get to the back.

Maybe I could drill them out and fish a wire down to pull new ones and tack them on the front?