Hi John, could you please also post your 3DM file (preferable with just the pieces adjacent to the wing juncture that you need help with) so that people can look at your geometry and give some suggestions based on that?

It looks like you have some curve structure in place that could be used to build a surface with Network or Sweep.

Another possibility is to work off the edges between the 2 surfaces and use the Blend command to put in a smooth blend surface between them, see here:
http://moi3d.com/2.0/docs/moi_command_reference7.htm#blend

- Michael