It helps to add the articulating neck during the build of the Torso.
Did you notice the shoulder pistons are visible in the photo?
Installing the “Pistonbase” and “PistonClavi” will make the shoulder installation easy.
It’s a hard detail to spot, but this Torso has been test fit with the Top-Stomach.
So integration with the Top-Stomach and the Torso will be easy next time, with just a little tear down of the Top-Stomach.