I've thought about it some; the way I see it, you'd need to re-engineer the wing halves to place the roots at the edge of the fuselage, make the wing sections that cover the top of the cabin into one piece and make it a part of the fuse by gluing it down. Then you modify that section and the forward part of the "turtledeck" into the green house, and make functional struts and their associated hardpoints on both the outboard ends of the wings (about 2/3 of the way to the tips), and another hardpoint at the rear landing gear mount for the inboard end of the wing struts. By the time you make all these mods, you've completely rebuilt over half the plane.

OR, just build it per the plans and make it an L-4C model. They were civilian Cubs pressed into trainer and coastal antisubmarine patrol service. You could re-cover it in Dk Blue above and gray underneath and make it an NE-1, which was the Navy version.