Re: international L 162 questions
It may be original or it could have been replaced years ago with an off-the-shelf generic ignition switch.
If it is the latter, then I would buy another off-the-shelf unit and next I would try the new key. !!! It may fit and work.
If not, replace the switch. Label the wires when you remove each one.
EDIT: I am also a professional, a licensed professional ! Thank you, thank you very much !
My cave location --> Western North Carolina