Thought you might like to see this. It is the original of what you have. I bought it from a guy that came up with the idea early last year. I bought the original from him, usedf it for a long time and still have it in my toolbox. Not a good picture but you can see its a prototype (vise grip marks and all). It was designed to be either screwed in with small screws or tie wrapped in or JB weld in. I found that the small screws used for it tore out of the frame when it flexed on a hard landing (but prevented the frame from breaking at the expense of the main gear). Worked best when screws were used to postion it and the whole thing JB welded in place. Used it till the Extreme stiffener came out.
There was another one like yours that was made from cast epoxy resin but it was longer and didnt include the spacer to put under the motor. I use a Align motor mount under my motor (alumn and all ready drilled).