Someone had this same issue about a year ago. IIRC, they had it repaired.
My opinion: Buy a new one. Chalk it up to bad karma, the convergence of time, space and spiritual dimensions., whatever....if
I repaired
my radiator, it would be fine until I was on a trip, 500 miles from home, in the middle of a wilderness, leading 10 others on a group ride....the repair would fail and ruin everyone's day and my wallet (Now we'd be talking towing, or at least getting home and bringing the trailer back to wherever I could have the bike secured...and then the storage costs...). Yep, I know, I tell a grim story. But, that's just
my opinion .
YMMV! And good luck with whatever decision you make. Oh yeah, when you order the radiator (or have it repaired), order and install a radiator guard. And if you don't have sliders, order them, too. Tell SWMBO I said it was okay and proper!
Some things we by as a preventative measure, with good reason.