Inventory with Upgradable Items and Varying Stats

I actually didn't know you can create scriptable objects at runtime. It turns out the tutorial is already instantiating copies of scriptable objects before adding them to the inventory. I just need to modify the stats when it's instantiated and save that data for loading later.

I'm having some issues accessing the variables of the current class though. Here's a small sample of how it's currently set up:

Item Scriptable Object (this is the base Item class that can be used as a template for different item types)

 public class Item : ScriptableObject
 {
     public string id;
     public new string name;
     public int maximumStacks = 1;
     public Sprite icon;
 
     public virtual Item GetCopy()
     {
         return this;
     }
 
     public virtual void GenerateStats()
     {
 
     }
 }

EquipmentItem class (this is an equippable item with a range of possible starting values)

 public class EquipmentItem : Item
 {
     public enum EquipmentType { Barrel, Breech, Head, Mount, Swivel, Base, Mod1, Mod2 }
     public EquipmentType equipmentType;
 
     public int startingMinFirepower;
     public int startingMaxFirepower;
     public int startingMinFireRate;
     public int startingMaxFireRate;
     public int startingMinTrackingSpeed;
     public int startingMaxTrackingSpeed;
     public int startingMinAccuracy;
     public int startingMaxAccuracy;
 
     public override Item GetCopy()
     {
         return Instantiate(this);
     }
 
     public override void GenerateStats()
     {
         // calculate stats
     }
 }

For my loot drop script, it's something like this:

 public Item item;
 
 private void DropLoot()
 {
             Item itemCopy = item.GetCopy();
             itemCopy.GenerateStats();  // this works fine
             itemCopy.name = "New Name";  // this also works fine
 
             int temp = itemCopy.startingMinFirepower;  // doesn't work
 }

Now if I try to access the name of the item, doing "itemCopy.name" works since it's in the Item class, but I can't access any of the variables in the EquipmentItem class like that even though I was able to put an EquipmentItem in the "item" slot of my loot drop script.

I could change it so that the loot drop script takes an EquipmentItem instead of Item, but then I wouldn't be able to put in non equipment items, like consumables, currency, etc.