I /did/ see the warning about vertex index 0 in the obj importer script,
but I didn't take it seriously enough. This fixes both the twisted texture
on a couple of faces, and the truly mangled tris when exporting (using
invisibl.mdl for testing).
There seems to be some problems with the UVs, only one frame is exported,
and various model params don't get set (eye position, size, bounding
radius, synctype, flags), but the size and shape look right in qf :).