Hellfire, lost the first attempt at a reply. :angry:
Anyway I am not sure what you are trying to do. As far as I know the only way to texture an OPT is to take the DXF you have modified or created and import it into ACE or OPTech. Then in either program apply the textures and then (eventually and after adding other things like weapons, defining what parts are what (bridge, engine, hull...), hangar entry/exit points...) saving as an OPT.
I didn't even know that you could import an OPT into Rhino3D without going through the "Convert OPT to DXF" stage.
Good luck, it is nice to see that new people are still starting to make OPTs.