Hi Jean-Paul, I was messing around with your wireframe a bit more and I thought I'd share one note that may be generally useful to you when trying to use this kind of "make skin over wireframe" type method.

It's regarding this area where you may have a 3-sided region you want to fill in:




You've probably seen before where doing a Network on those 3 sided areas separately will make some undesirably bulging/puckering like this:



That happens because the curve pieces are of different lengths, and the upright profile can kind of sway back and forth as it gets merged with the other pieces, making for a kind of twist in shape.

But you can use Sweep with a special option enabled as an alternative which will work better in this situation, if you've got a simple planar profile piece like this:



What you do is select that planar profile, then run Construct / Sweep, and activate the "Maintain tangent" option:



That will cause the sweep to get generated by keeping that profile in the same plane and marching it down the rails and getting intersections with the rails and the plane, if you look at the control points of it you can see that regular planarity to them:



(EDIT: you would actually have seen it even more clearly if I had taken a top view snapshot, here to see that the surface control points are all arranged on parallel planes).

That's different than a regular sweep where the profiles kind of "slide" along the rails and can get that kind of twisting introduced if they are of different lengths.

Sweeps that are done with the "maintain tangent" option will more rigidly preserve the shape of the initial profile, which gets this kind of a result even when doing them as 4 separate sweeps:



- Michael