Tick Talk[Moderator Emeritus]
2296
there may also be
either 154 or 54 stamped on the case body to confirm the two parts match. The casemaker was registered in 1947 so that establishes the earliest possible date.
Edit: here is an example from the same case maker but for Ref 4539 XXL of 1949. The numbers match the last 3 digits of the case serial number, confirming the back and body belong together.