I had just the top half on one of my carbines since I had a 37mm hung below the barrel. I ended up selling the 37mm and now I'm left without a bottom half of the RIS. The guy I got the top half from said he'd sell me the bottom half for $40, but I didn't then and I can't find him now.
I'm looking for something cheap, it can be scratched, painted, chipped, whatever. I only need it to hold a Knight's grip and a couple short panels, so the outer notches can even me screwy I don't care as long as it will hold itself in. I'm not easy on my gear anyway, so I'm not about to buy a brand new one if I can rig this one- it's a backup rifle anyway.
I can PayPal or trade, or whatever, just let me know what you've got and what you want for it.