Can't thicken surfaces

Vitul,.. there are some overlapping surfaces in the Rhino import.. I offset and knitted them and added some extrusion and plane to make it solid..... unfortunately, the minimum radius of curvature and the singularities will not allow for this to be thickened or shelled.. so,.. if you look at the image attached,.. you will need to fix the areas highlighted in yellow.  (image and file attached)