Trying to do weld tabs on a 3d profile metal sheet with 2015 version.

I wish I had 2018 with automatic weld tab feature!

I tried:

Lofted bend of the top and bottom 3d sketch curve . It works with some geometries , but not with everything, at least not with the attached curves. I can select the curves but I have a self intersecting geometry. I doesnt like sharp edges, so I have arc fillets on corners.

Any guidance on how to model in sheet metal a curved 3d metal sheet with weld tabs is appreciated. I am flexible about the tabs shape and position. However not flexible on the curve general profile. See attached file.

Ali T.