Hello, all, first question from new user!!

I have created two 3D curved surfaces in a part drawing, from which I wish to create a solid body, extending from the surfaces to a chosen planar surface

I have tried thickening and surface extrude, either on a single of the surfaces or on both simultaneously.

Thickening gives me a body that extends roughly perpendicular from the individual surface in a specified thickness - not what I am looking for.

Surface extrude gives me the shape for which I am looking, but only creates surfaces, not solid bodies.

Any ideas? Thanks in advance for any help!!

In the attached file (part drawing, SW 2019 SP3.0):

   -  the 3D surfaces colored orange/rust (right curved face, left curved face) are planned down to the green surface equal to front plane.

   - Boss-Extrude1 and Sketch1 (including Sketch Picture1) are hidden.