The problem I'm having is getting a uniform thickness
The issue will be, that you have to change the topology of the mesh. The light gray mesh right silhouette consists of 3 lines, a uniform thickness hull will need circles to be uniform. Eg take the corner of the light-gray section between the two lower blue lines and draw a circle around it to see the corner part of a uniform thickness hull.
With this in mind you can construct a hullmesh by a selection of geometry objects. In 3d you need a box for a plane, a cylinder for a edge and a sphere for a vertex. The combination (union including the original mesh) of all this will define the hull mesh with a uniform thickness.