Hello François, Mostly just kidding about the CAd part. It looks like you are using both the kit and printed parts so I didn't realize that the frame was printed also, I may have missed that along the way. Do you use a 3D scanner or reference probe to copy the kit parts? Not being familiar with the kit I was going to ask if the Airfix kit included a molded version of the wood structure, not something usually found in box kits. I gather that you have good reference material for the internal wood frame construction. Yes It is pretty surprising that there wasn't some warping or misalignment of the original kit parts, especially in this scale. Thanks again for sharing!