Well, there you are, at the top of the collectables section
"Idiots guide to classic airgun strips " by ggggr .

I must qualify as the advice was accurate and easy to follow.
Initially I was apprehensive about removing the end cap as I could feel spring pressure on it when loosening off. So, I held a screwdriver blade against the mainspring coil and could not detect movement when unwinding the endcap.Onwards.......
Tomorrow I will complete the strip by adapting an old pipe style sash cramp as a spring compressor.

Thanks for the assistance