Hmm it's not the Do-217 Krusty, I know what aircraft you mean though, it's Heinkel He.....?
I have a modell of that too, I'll post some pics aswell.
They placed 4 engines in 2 pods because (I believe it was Goring?) didn't want a 4 engined bomber.
They solved the "problem" by placing 2 engines in each pod, but it had lots of problems (it kept burst out in flames)