What about using a plastic container, cut it to shape. Think bottom 1/2 of a tackle box, tool box, rubbermaid container, that would be easier and cheeper than fiberglass.
98 uzj100. Factory rear-ARB front locked 4.88's. ARB Bull, Warn 9000, Irbis rear bumper, Slee sliders and belly pan. OME t-bars w/863 rears, HID, XM