If you buy a low profile gas block from about 5000 differnt places for $20-40, I have a 12" Yankee Hill lighrweight free float quad rail that I will make you a hell of a deal on.
They ran about $125 when I bought it, Make me what you consider a fair offer to you and it will likely be yours.
It probably has a little wear but I can't say I recall any. Includes barrel nut, jam nut and everything needed to install it except a low profile gas block and a flip up front sight if you intend to mount irons.
Here is what they look like, can dig it out for actual pictures if your interested.
http://vtsupply.com/yankee-hill-free-float-quad-rail-forearms-yhm-9631-or-yhm-9638.html
