The manufacture of our engine requires quite a few very specialized tools and processes. The unusual shape of the trochoid housing's surface (sort of peanut-shaped) is nearly impossible to build without a CNC mill, and the side seal grooves are so thin and deep that they also take a special tool. In addition, once created the wear surfaces require plasma spray coatings to withstand the extreme operating conditions.
With all of these requirements, it is a difficult engine to build in small quantities. And that assumes you start with reasonably good castings, which are also a challenge to get in small quantities.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.