Um... hm... I haven't experienced this particular issue, though I have noticed something that may or may not be related (it's sort of like this but in reverse).
I've a script that changes the material of equipped items: when I run it on my weapon, the paper doll does update, but the model in the game world doesn't. If I unequip and then re-requip the weapon, the model then updates properly.
Armor does not have this issue.
Might not be related at all, but I thought I'd mention it. I have all the DLCs.