This is an opening door on the nose of this model. If you don't care if it opens it will be much easier to repair. If you want an opening door then it needs to be reattached to the hinge mechanism.
But, as Jay and others have said, if you don't look inside, you don't know what you have. Removing a shell is not difficult and could be as simple as removing 4 to 6 screws. The chassis, motor and trucks lift right out of the shell if it is sitting upside down. Make a cradle out of something (foam, cloth between some supports) so you don't mar the paint or damage any roof details. A very simple and good start to learning about your brass models.
butch
