Charlie,

Welcome aboard and congratulations on finding a piece of single shot history.  Oddly enough, CC Johnson's first name was Charles and he was sometimes referred to as "Charley" also.  His grandson, Jerry Johnson does frequent this board and has been gracious enough in the past to provide information from his grandfather's shop records.  In order for him to do this, you will need to remove the fore end and provide the numbers and letters marked under the barrel, which provide in Johnson's own coding when it was made, what barrel was used, and in the records further information about who it was made for and sometimes even more information.  Let me take just a quick second to publicly acknowledge Jerry's work on this and thank him for the effort to which he has gone to preserve this information and make it available. 

BTW, there was an article in the Jan/Feb '06 issue of the ASSRA Journal (a benefit of association membership) which described CC Johnson's work.  Perhaps you could contact our archivist, Rudi Prusok about buying a copy.  

Good luck and Merry Christmas,
Another Charlie ~ the Green Frog