For a first attempt, I think you did well. The main problem I see with a cowl on the SSE is that you need to go from a square shape to a round one in about 4 1/4". A large 2 to 2 2 1/2" spinner helps ease the transition. Chuck, you may look at putting holes in the plywood ring behind the spinner. Then you can access the bolts that go through the engine mounts to the firewall. You might be able to remove the engine and mounts as a unit.