Very well done sir! New subscriber here! I just got a HD10 and would like to do similar. You got me very inspired as to how to do the base bracket to hook to the plow to the Defender. Thanks!
At the very front, there are some good places where to bolt, but under the frame, it's another story. I think the key is to make the small vertical tabs contouring the sides of the frame, which is what you did. There are no nice places to bolt that will hold true in such a thin metal tubing frame.