Dalton, the door locks on our planes are simple locks that can be bought any place that sells file cabinet locks.
Nothing special about them and to be honest, they don't offer much protection.
A hard pull on the door handle will break off the little tab on the handle that the arm of the lock engages or the window can easily be broken.
Even if you add a door lock don't leave valuables, like headsets, in the plane on the ramp like you might have done when it was in a hangar.