its a upgrade system and not a model switcher
model switcher works like this:
-you are able to switch a Item (Glavie in this case) in different degrees not only "upgrade" to a static item.
-there should be 1 Scroll for every degree only (Model Switcher D1, Model Switcher D2 etc) NOT (Model Switcher D1 (Glavie), Model Switcher D1 (Bow) etc)
this isnt possible with your system and btw a better version of this upgrade system is already released by me