Hi,
That is the basically the thing I did except I welded the ends inside the bucket next to the upper edge. That way there is nothing to remove off the machine when you change buckets. I did not tie the two chains together with a cross chain, but made them quite loose, so they could flop around.
Joe
You bucket looks like a cribbing bucket. We use them to crip out the ballast between crossties on the railroad. They do pretty good for digging narrow trenches too.