hi michaelvader -
I have attached links to the build threads where I have depicted how the models were built using the balsa 'in fill' method I first saw another modeler describe.
Search the name : Dave Duckett at virtual aerodrome or at the Guillows site I have linked above to see his work also.

These models are for display only as I have built them. The objective was to see how well the Guillows kits were executed wrt to scale appearance in overall form, and then to augment them with scale details and
modest enhancements.

This last model is NOT a Guillows product - the F/A 18c is from Today's Hobbies
I hope this helps. Please check the links or browse the Guillow modelers forum for more information and photo's