Hi Nos, so basically something along these lines here:



Each piece can have some contouring to it, but it's trying not to do too much in any one individual surface.

See this recent thread for some tips on making some slightly cupped surfaces using sweep:
http://moi3d.com/forum/index.php?webtag=MOI&msg=4296.5


When you've got a set of surfaces that are all overlapping each other like this, you can use the Construct > Boolean > Merge command to form them into a volume with one command trimming away the outer part - it's also possible to use the Trim command as well but that will involve picking the pieces you want to discard more manually.

So that builds a block with sharp edges like this:



Then you rely on filleting to do the more tightly bent transition areas:






You kind of have to give up some immediate control, you're going to focus on drawing some broader shapes of the piece instead of trying to actually directly draw profiles that contain the transition areas in them already.

Also the "Shape" option for fillet can be useful for this kind of a thing - try setting Shape: G2 Blend to build a kind of more natural looking connection surface instead of the regular fillet surface that has an exact circular arc shape to it. You can also then adjust the "Bulge" slider to tweak the transition areas in addition to setting a radius value.

- Michael