Alright. So I have a custom weapon set up - it's got a custom mesh (I got permissions to use http://www.nexusmods.com/skyrim/mods/4474/?), and I have both .nifs - the default and the 1st person, in this directory:

Skyrim/Data/Meshes/ImmersiveQuests/Bonecrusher

The name of the weapon is Bonecrusher. I renamed the original .nif from skyforgesteelmace.nif and 1stpersonskyforgesteelmace.nif to Bonecrusher.nif and 1stPersonBonecrusher.nif. The texture paths are the same as before - they point to the default steel warhammer texture. Skyrim/Data/Textures/Weapons/Steel and then steelwarhammer.dds, steelwarhammer_n.dds, and steelwarhammer_m.dds. In the CK, I have my custom weapon set up with the proper model path - Skyrim/Data/Meshes/ImmersiveQuests/Bonecrusher/Bonecrusher.nif, and the 1st person model as the static 1stPersonBonecrusher, which has the model path of Skyrim/Data/Meshes/Immersive Quests/Bonecrusher/1stPersonBonecrusher.nif. Yet, when I use the weapon in-game, it clearly has the right mesh, animations, and sounds, but it is invisible.

What have I done wrong? I'd appreciate any help with this. It's the last bug I have to iron out.