Summary

I modified / remixed from https://www.thingiverse.com/thing:2430122 to a for me usable version.

I use a Raspberry pi 3 model B with 2 USB stick, one SLC- Stick is 72 mm long, therefore it's 18 mm higher
The cutout for the network cable went to the power connector - looks better
You can detach the top to get to reach the connectors

The Files:
1 Ventilation Base The TARDIS stands on it, I fastend it with hot glue to make it detachable
2 Fan Holder for 30x30x10 mm fan, glue it to part 1 when you see where network cable should be
3 Lower Body use M3x25 or M3x30 screws with nut, it makes it easyer to mout the board
4 Upper Body glue it to part 3 when the board is mounted
5 Main Top The top of the TARDIS suitable for a 5 mm 120° LED, I fastend the LED with hot glue
6 Signs 4 pcs. You glue them into part 5 (I printed the letters in white)
7 Top Connector Press it into part 5 add glue it if you like
8 TARDIS Hat glue it on part 5 when you mounted the LED, print it moreless fine

Remarks:
The fan is 12 Volt, but works good at 5 Volt, pin 2 or pin 4 5V and pin 6 GND
The LED is connected to pin 39 GND and pin 40 GPIO21 with serial resistor ( I used 470 Ohm)
To bring the activity LED to GPIO21 add "dtoverlay=pi3-act-led,gpio=21" to /boot/config.txt