Thanks for your original post. I am doing my fourth annual and found this issue. It must have been broken for a while because the vertical part of the broken angle had sawed into the head of the 10mm bolt that fastens the horizontal part of the angle to the rubber shock isolator.
FYI I checked the original bracket with a magnet, and it is non-ferrous, probably aluminum, which is what I replaced it with. I think the problem is that the bolt holes in the angle are offset, and if the offset is not correct there is a constant force pulling the angle causing it to fail.
For anybody else who has this issue: be sure to put some material under the angle before you remove it because if anything drops there is a good chance it will go into the flywheel area where the generator, tach, trigger and ignition power coils are.
I had to disconnect my oil tank hoses to gain access to the fasteners.