Have you had any luck actually giving assists in crafting them? I tried it with my friend who has 120 crafting and it wouldn't let me craft the amulet. It said I "must have 99 crafting to make this amulet" or something along those lines. I've seen others with same issue on other sites complaining about this. I wish it was assist-able like invention is for making the alchemical hydrix. I guess maybe this is a bug that needs to be fixed?