It is very possible to produce a Q-40 with a foam wing.
I recently built one of Matney Models Napier. Kevin is the owner. I am now building one of his AJ-2.
Napier construction is shown on a forum in Pylon Universe.
I just started another construction forum on the AJ-2. The AJ 2 forum is on the NMPRA site.
Below is a link on Matney Models:
http://www.matneymodels.com/qm.html