snip
Yeah, add a top part to the handguard.
Selector switch looks incredibly odd. Imo, you should change it.
Everything about the stock looks bad. You should change the stock design to resemble a Magpul CTR stock.
Pistol grip looks stupid, I think a Magpul MIAD grip would look better.
I think that, you should also switch out the regular mag for a Magpul PMag.
Clean up the receiver, take what I said into consideration, fix the ironsight, and get rid of the horrible flash hider and I think the model would look alot better.
MIAD and CTR are both shown in the below picture.
Pmag
Birdcage flash hider, would look better than whatever you have on the gun atm.