https://thegreatmodel8.net/

Gang, why am I not able to remove the stock's smaller screw? Is thee a trick to it? I am afraid that I'll booger it up if I keep trying without success. I even used Kroil on it but with no luck.

Welcome from North Florida. Be very grateful that the screw will not budge. It is not a stock screw.It is the screw that holds tension on the mainspring. The large screw is the only one holding the stock on. If it is tight and will not come off after removal of the large screw try giving it a rap with a rubber hammer.That should break it free.
If you do a complete disassembly the mainspring screw can be removed when tension is relieved. There is a manual you can download on the Great 8 website and some videos of assembly disassembly. Good luck.
Joe

Thank you sarge! You saved me making a mess of things.