712, in common with all other Tigers, has what appears to be multiple different Fahrgestell (VIN) numbers stamped on different components. While the official Fahrgestell of 712 is 250031, the following have been found on the vehicle.
Hull - 250058
Turret - 250034
Mantlet - 250030
Cupola - 250029
This is because both the Heeres Waffenamt and some part manufacturers used the same production run number ranges. More detail on this and surviving Tiger serial numbers can be found over at Rob Veenendaals Panzerbasics site. In addition, images of 712 numbers in various places can be seen in the gallery at Armour Journal online magazine.
The animation below shows how the stamped numbers were applied. Click 'Play' button to start.