Hey ,
im just start learning the UE4 with your pack. Thanks it’s really awesome. But i struggle arround with the replacement of meshes inside a blueprint. I took the elevator layer “floor” and changed the mesh in the details tab to another mesh to let the structure and the mechanism untouched. I also could give it a new material, but i cannot scale it up. Some meshes can be rearranged and some not. Can you tell me why? Sorry im just learning… 
And maybe how i can fix it?
Thanks!
-gm