As much as I don't like stripping a new engine I have come to realise it's a wise move. I bought a new Enya 45S-M direct from the factory and it was loaded with fine Metal dust. I do mean loaded. Enya engines are always immaculate from my experience, I guess this one missed QC.
If Enya can slip like that then they all can.

With e Bay purchases I have had small screws and a big chunk of cardboard inside engines. One of those things.