PRE 1960 (ASC172 - Pre 1960)
Early on, Cessna installed the lock below and off to the right of the handle, in which case our replacement lock has a cam that reaches over and up to lock the handle.
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Pre 1980 (ASC172CDE)
Later on, they installed the lock directly below the handle which reaches straight up and locks the handle.
Early Style Cabin Door
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Post 1979 (ASC172CDL)
After 1980, Cessna installed the lock directly to the right of the handle and had a arm that reached over and put a pin the in the handle.
Late Style Cabin Door
If you would like to confirm which version have, please submit a ticket with a picture of your door panel and we can advise.