<img border="0" alt="[typing]" title="" src="graemlins/yltype.gif" /> Hairy,
The pin sticking out of the front of the sear is the disconnect. It keeps the gun from going full auto. As long as the trigger is held back after firing, the top of the trigger lever keeps the pin retracted into the sear. When you release the trigger and the lever swings out of the way, the pin pops out and when you pull the trigger again it presses against the pin and rotates the sear to release the firing pin.
email me at hhclark@academicplanet.com and maybe I can help you get your gun to shooting. <img border="0" alt="[king]" title="" src="graemlins/r.gif" />