How Do I Auto Swap An Item On Pickup

Basically I want that when a specific item is picked up (it's a custom helmet) that the item will equip, and put the headgear in the player's inventory replacing the crown. I would do this on a one tick delay but I fear that this would make duping of the items possible. Any ideas on what to do? Forums are not very active so I dont expect a response but any help is appreciated. 

This is my current code by the way.