Or welding a short piece of angle to the back of the fork forming a "v" so that it rests on the edge of the blade of the bucket.Great welds. Just a little concerned with just one point of contact for the top. Won't it bend if you just lift with one fork? Maybe I am missing another support in the picture.
When I built mine, I ran the tubing all the way to the side of the bucket and welded plate to the edge of the bucket. I also have my forks resting against the leading edge of the bucket. Takes all the torque out of the equation.