I build, you build, we can all build with Coroplast.
I have built many Aircore models for people and have started building my own designs from Coroplast material. (Cheap sign material) Here is a look at the first Coroplast model I designed. Note the tail fin installation, the cowl type nose cover as well as the screwed together fuselage. No need for a big hole in the top if you can unscrew the fuselage to get inside.