With all your help, have got the stock liberated from the gun. As it turns out the threads on the barrel band are good! After removing the nut, the screw was still secured by the threads on the band, so not sure the purpose of the nut. I also found some more markings on the wood and metal, so have included those. One thing, the one picture with the yellow circle is a pin that drops out easily. I assume this is not a problem?
My next step is the stock cleaning. Have found the Raw linseed oilon Amazon, but haven't been able to find Natural Turpentine. What do you use?