In the books, the character of Dampfwalze ("steam roller") was a very burly, muscular white kid because at the time the Schreckenstein books were published (early 1970s) children of color were very very rare in Germany. If there had been any attempt to include minorities, it probably would have been a boy from Turkey.
The drone the boys use to trigger the Castle Rosenfels fire extinguishing system is a DJI Phantom 3 with custom-painted rotors. In real life, it would likely not have survived a direct hit by a pillow or the tumble it takes escaping out of the window.