Well if it has the emblem and the hexigon speaker bushing then it's a CT.
The serial number lists are what they are. The manufacturers lists are not 100% accurate, they were just keeping track of inventory, etc.
You SN would be a late BT SN which could have been the transition time to the CT.
Don't think of SN lists as "absolute" as there are always exceptions and sometimes manufacturers end up revising their SN lists.
Leblanc/Noblet was great at what appears to be making xxx numbers of clarinets per year, putting the unsold inventory on a shelf until some later year had the demand for them to pull them off the shelf, or just leave them there. At times, someone would just start a new serial number list in the middle of another SN list until someone thinks .. whopsee. You get a lot of abnormalities, thus one reason I always want to see pictures of the instrument so identify certain characteristics of it to understand what model it could be, although some models are very light evolutions of a previous one.