Looks like your missing the pilot jet (long brass tube), the float, float needle, float screw and float pin (assuming you haven't removed those items). Looks like the main jet is in it. I've never been able to locate a replacement pilot jet unless someone happens to post one for sale but most don't realize that the pilot jet pops out anyway. You can try a clone or maybe go with a Dellorto SHA real or fake. You would also need an intake adapter for the SHA.
For some reason, I picked up another Express. I guess the price was right. Getting those old carbs cleaned to the point that they will run right can be a pain. I may have to go full SHA on it. (edited)