>>2938248
>Did they just make skeleton and put sheets and cuted excess out then just drilled?
Basically, yeah.
Back in the old days, yes, they would first build small wooden model for aerodynamic tests, then full-sized wooden mockup, then used it as a shoemaking last to make stencils.
Then they would build a couple of non-flying prototypes using their stencils to see if it all fits, make adjustments, build proper toolings to bend metal exactly right and hold it in place so that workers could rivet it together.
Only then they could get to work on the actual prototype and finalize the design.

Now you can use 3D models and skip right to toolings.

The most complicated part of industrial design isn't making the product or designing the product.
It's designing the machines, molds and and tooling that allows you to make the product reliably and repeatedly.

This is also why you can't restart production of ancient designs that scrapped their toolings.
Most WWII plane replicas are just shells made of fiberglass fitted with modern engines because nobody has funds for a authentic production restart.