It's dangerous to mod alone! Here, take these dummy object meshes. These should behave just like the dummies Bethesda made: they are invisible in-game, and can be used as placeholders for leveled or decorative items in the Creation Kit. Archive contains these dummies:
- Dragon priest mask
- Crossbow
- Bolt quiver
- Dragon claw
If I make any more dummies, I'll add those, as well.