"C:\Program Files (x86)\Steam\steamapps\common\CM2013\Repository\LO_weapons\hl2" Place the custom weapon files in here. They wont work however until you goto the configuration tool and select "Activate Cinematic Mod's Weapons" and hit ok, then re-open and unselect it then again hit okay. I'm pretty sure this injects the files somewhere I just don't know where.
I have also only done this for the Valve weapons and not the Cinematic weapons. I'm pretty sure HD_weapons are the cinematic weapons. Also I have not tested this with VPK's and I still am clueless to this part.
[Edit] Found this to "C:\Program Files (x86)\Steam\steamapps\common\CM2013\Character Pimper\AutoPlay\Repository" pretty sure same process but for characters.