1956 tail light lock help needed

[Lexi]

Hello all. Hope the holiday season has been good to you and your family. I need help from members regarding an after market Cadillac accessory from the 1950s. A company manufactured cylinder locks that took the place of the 'push button' OEM reflector, for the left rear tail light assembly. Does anyone have any information on them such as details on how they were installed, original instructions (would be great) and/or tips as to how to proceed? For example were they 'plug and play' or was some permanent modification required? Also, anyone know where there is one for sale? I seem to recall different models being available with some perhaps even being made for vehicles other than Cadillac. Been awhile since I have seen one and some installations were not particularly becoming as I remember, which leads me to think that sometimes the wrong locks were installed. Any help appreciated as there are a couple of us up here that are interested. Any information on what would fit a 1956 Cadillac tail light assembly is required. Thanks for any assistance provided. Clay/Lexi