I just had a few of these made. Is this something anyone else can use? I just sent my drawing to the local waterjet place, and they cut them out. They are pretty cheap to have done, but there was a $50 minimum, so they made 4 for that price. I will probably end up selling the 3 extras at some point, but if anyone needs one and can get them cut locally, I can send you the dwg file. I just used round holes for the mounting bolts because square holes are expensive to cut on a waterjet.
Edit: I got a request for the drawing, and it is pretty small, so I am attaching it to this post.