Mesh change at runtime or in editor

I've tried simple code:

 public Mesh simpleShip;

     void Start()
 {
     Mesh mMesh = Instantiate(simpleShip) as Mesh;
     gameObject.GetComponent<MeshFilter>().mesh = mMesh;
 }

I assigned the simpleShip to a known working mesh (in another project), it compiles and runs, no warnings at all, it assigns it to the MeshFilter successfully, but the mesh never changes. I also tried assigning it directly in the editor, without the script.

There was no meshFilter when I started, so I added that too, of course. Is there another, overriding, method of mesh control? These are the only 2 methods I know for mesh assignment.