No: there's "normals" on polygons, if you look at them from the inside, they won't be rendered. If you were to do the inside view on, say, the old hercules model, you'd see a bunch of polys flying around you, the ones that for some reason have enough angles so they'd face the camera. If you add the cockpit in there, you'll have the cockpit rendering fine, and that mess of weird isolated polys around it.
Honestly, adding a cockpit is not that difficult anyway ( well with max, at least ), if you're up to reconvert a ship, you might as well spend some time doing the job right

About bob's detailbox, how does it work?