There's more than one way to skin a cat.
If it were my bike and the bridge looked like that, and the area surrounding the bolt was solid, and I only needed 2 millimeters, I'd pull out my Nicholson bastards and make them earn their keep. 2 minutes later later I'd remount the brake throw in the wheel and be on my way.
Whether the OPs bridge has enough meat to spare is a judgment call, but if it has this kind of bulge in the middle it probably does.
__________________
FB
Chain-L site
An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.