Does This Make My Caboose Look Square?

In a previous post, I made the remark that a caboose is nothing more than a box on wheels.  Today, that box began to take shape, as I finished constructed and attaching the two side walls and two end walls of the caboose.

Each end wall contains a door (constructed from cereal box cardboard, paper, and clear plastic):

Each window contains a "glass" pane, cut from a piece of clear plastic, with a piece of Scotch tape applied to obscure the view into the caboose.  Since there is no interior detail, I don't want a clear view to the inside.

Before the long weekend is over, I'll have the corner joints sanded and filled, the roof installed, and hopefully will have started on the cupola.