W116 Steering Lock question and tip
 

My 1979 300SD strands me in a parking lot with the dreaded key wont turn problem..

Had it towed home and tried all the tricks to get the key to turn so I can get the tumbler removed... Finally what worked was an air chisel with a blunt chisel,,, I removed the instrument cluster and while turning the key, used the chisel to heavily vibrate the lock mechinism thru the instrument cluster opening.. Took about 10 seconds for the key to turn...

Now my question... Should I be able to use a large flat blade screwdriver to lock and smoothly unlock the steering wheel by turning the slot where the tumbler would have enguaged. I am being careful not to push it in too far and interfere with the lock mechanics... My lock will not unlock very easily. I think the lock is the problem and not my tumbler... The ignition tumber is smooth like Buttah..

I am going to change them both out but was just wondering..

Also found out that Mercedes cant order a matched tumbler for my car cut to the VIN number... Using a copy of my title he tried to order it and was informed that the car was too old and I would have to use a generic tumber and key...