The door has arrived. It is a standard "Chicken House Door", which is available at numerous online shops.

The brain looks straight forward: two connectors one for power supply one for the motor. 

A motor driver (SA8301) and an unmarked MCU populate the fron side. 

On the back there are three green LEDs and a photo diode which sit behind the window cutout below the "Chicken House Door" label.

To make the door work for this project I could use the board and just replace the MCU but the easiest rout will be to do a complete brain transplant.