British Flare Tip Rocket dating?

Hi everyone, I have what i believe is a late 50's British Flare Tip Rocket. I am wondering if anyone can tell me the exact year? It has the proper Patent #, but it has an "S" stamped on the underside on the left side of the shaft? I cannot seem to find anything that explains the "S"? Thanks for your help.
Sean

Still a mystery



https://www.google.com/url?sa=t&sou...n_lzl-e92IEfPdeOA&sig2=Ag5Z1pJRMDuX1GkOZASfyA

Thanks, I didn't see that post in my searching.
Sean

s stands for Shiny!