The Bushy AR15 would be worth about $700 since there is no federal AW ban in effect anymore. However, there are still some states that have their own state laws that would make a pre ban a bit more valuable. Had you sold this weapon a year ago you would have gotten twice as much.
As for the second upper with the FN upper reciever and Colt barrel it would be a bit more difficult to guage what value it has due to the limited information. Is is a pre ban, heavy or pencil barrel, civilian or military barrel? There was a discussion a ways back on whether or not FN produced uppers for civilian sales, with the general concensus being, no, none were produced for the civilian market. If it is a true FN with a Colt barrel then it is possible that you have one of the M16 uppers. Those aren't particularily valuable since the round count would be typically very high. A guess on your upper with no bolt /chargin handle would be about $250.
The full size stock isn't particularily valuable these days as well. A new one will run about $55.00. A lot of folks have extra ones around due to the popularity of collapsible stocks. So I'd figure about $30.00.
Depending on your location I could see you getting about $950-$1000 for everything.
Good Shooting
Red