I'm not trying to look a gift horse in the mouth, but it kinda is a communist thing.. We're not trading, selling/buying or bartering..
It's the same thing that didn't work in the beginning, here. Without keeping score, it's kinda hard to keep balanced.
It's like the "got a cig-give a cig, need a cig-take a cig" jar, like we all did in college, when we were all sharing apartments and renting rooms in trailers, with the cigarette bums who liked to smoke more than paying for them.. You still had to have a monitor to keep the bums from doing all take and no give.. You had to give three before you could take one, and you weren't allowed to take more than three before you had to contribute again..
(That worked well in curbing the "aw, man, cut me some slack" routine that kept me from enduring the eternal guilt trip from every pothead that never had a joint, er uh, cigarette..) I don't miss those days...
I'll put something up. Not sure what I have yet, but I'll put it up.. (No AR parts.. Sorry. My last AR was an "issued" A2.)