I shape...I mean I design that 3D file with the help of Marcelo who told me what he did himself and what he want after his first back yard board. Here is a picture of that board done in action....not bad
So there is a movie of the board I design for him.Please, have a look on that board he is going to build soon.
As I said this design is perfect

.... but I still waiting about your own advice about it. Demanding customers make accurate craftman.