Steering column lock?

Hi all,

On my 1976 KZ750, there's a keyhole on the steering column that I assume is a (surprise) steering column lock. Is this typically the same key as the seat lock or ignition? Neither seem to work for me.

Yes, from the factory one key opened fork lock, gas tank, seat and of course ignition. Plus, if key goes in fork lock you may have to move slowley each direction for tab to engage slot.