The Gemini-sponsored WFMOS Feasibility Study investigated a wide-field, prime focus installation for the Gemini telescopes. As constructed, the Gemini design allows for multiple, interchangeable telescope top-ends, although this capability has never been implemented. Constrained by a particularly challenging top-end mass budget, we proposed a new top end specific to WFMOS, employing a carbon fiber reinforced plastic structure. An innovative, out-of-autoclave manufacturing process using balanced pressure and liquid heating and cooling enables high-specification, large CFRP structures to be constructed suitable for incorporation as fundamental parts of telescope structures. Advantages include low weight, enhanced overall telescope stiffness, and cost-effective construction with on-site final assembly. We describe the manufacturing process and the proposed top-end structure, as well as highlighting the advantages of this type of structure and material for large and extremely large telescopes in general.