>But really I would think building in more simple pieces, one for the main body and the tail fin as a separate piece would be more of how I would go.

Yep, it seems it is the only way (pretty much like the real aircraft in fact). I try to avoid doing this though because it is much harder to sent up geometry wise and you tend to end up with meshing flaws once exported to a polymodeller. Even though meshing in MoI is far better than Rhino it still has its problems at joints and I really want a nice smooth clean mesh.