It's the MA5C ICWS, not OICW. The OICW is the pulse rifle form the Half-Life 2 beta, which was replaced in retail by the OSIPR. Still, it looks almsot exactly like it does in-game. Now make the M6G. I dare you.
This is a very cool weapon. I love the integration of the 98 Bravo's receiver top into the body of the gun. You gotta look closely to see it, put it's there!
The thing you said didn't seem right was the rails on the top and head of the gun near the barrel. Not that it's wrong, it actually looks kinda cool. If you melee someone with that, it would tear at the flesh, dealing more damage. Great job none the less!