I have ordered a new lock as well as a new tumbler. As I have 3 W123 cars (coupe, wagon & sedan), I have a lot of experience changing the locks and tumblers. It is just aggravating that these 3 year old genuine MBZ parts fail so quickly. I think the early security bezel was pushed on while the late was a screw on bezel. I have the screw on type (1985).