ORIGINAL: opjose
Yup that's the very one!
My only addition to this excellent idea was that I added a small ply cross brace that goes between the top of the "o" (where you see the vertical line ) on back to the firewall, and some small wood screws to further brace the angles you've put in.
The SS EP is an excellent flyer with this setup.
There are 4 triangle stock braces on the bottom for more strength. I'ts strong enough that if you apply vertical pressure to the prop shaft, the original mount rails flex. I used balsa tri-stock and CA glue becaise I wanted the mount to tear away in the event of a bad crash, in order to protect the motor. A friend of mine retained his by running long screws back to blind nuts in the original firewall, so that he could adjust the thrust angles easily. I had to put the washers you can see at the top, behind the X-mount, to increase the down thrust after the initial flight.
CR