Reproduced a close copy of Toms cab, using his images to reproduce curves.
Note that the two "acorn" shaped curves must be trimmed apart at the North and South poles, into 4 curves, for network to work. (Or kept separate during their creation.)
One-half "acorn" curve was created with two blends. A horizontal line segment was placed at the North pole, and a vertical line segment was placed at the squircle intersect point, and a blend done between. A second blend was done from said curve, down to a horizontal line segment at the south pole. Join for one curve.
Mirror and rotate for other 3 acorn half curves.
Rounded square, squircle, and lower circle curves were also created. The lower circle had to be a bit larger than the sketch IMHO.
Select all 7 curves, and do network.

Still attempting to load my old purchased copy of Keyshot 6.

- Brian