Very good question. Thanks for asking for everybody else. I gave the link to the hackaday project page below in the comments too:https://hackaday.io/project/164666-building-a-spitfire-model-plane-with-my-son
The project page contains a zip file called
Spitfire CAD files for converting to other formats.zip
I basically gave the entire project on a tray for free. Anyone can copy the dwg files, modify them as they like, plot the planar projections or export in any format on the market. I did not convert them myself to dxf since people have different machines and they need different formats, sizes, orientations and support bases. Maybe somebody would like to mill one out of aluminium for creating a sculpture of some sort for example.
Have fun and post pictures with the build :D