Removing hard brake lines from frame bracket Options

[6gsillyca]

I need some help removing the hard brake lines from the frame bracket. I got some SS lines and am trying to take off the stock rubber ones and it just isn't working out...

I took the whole brake assy off (caliper/pads/rotor) and "drained" the fluid out of the line (let it drip into a jar). I got one side off (fronts only, haven't started on rears) but can't seem to get the other off. I have a pair of visegrips clamped onto the bottom under the bracket along the solid part, just under the flare nut, and that seems to be gripping ok.

The part I'm having trouble with is the 10mm nut on top of the bracket. I got the first one off by using another set of visegrips and just muscled it, but the 2nd one keeps rounding. I've been at it for the last 2 hours, broke a wrench trying to get this sob off and have cuts all up my arm from when the nut rounds off and my arm scrapes inside the wheel well... Visegrips don't seem to be working on this side either as they just round the nut off more.

Any help? Is there such a thing as a "3 point" open end wrench. All the ones I have are just 2 points with a curved middle.