Show and Edit Attributes of my list of structs in EditorWindow.

Hello all, What I'm trying to do today is make my own editor window where i can add and remove a custom class from a list.

here is my custom ItemClass:

 using UnityEngine;
 using System.Collections;
 using System;
 
 [System.Serializable]
 public class ItemClass{
 
     public bool expanded; 
     public string ItemName = "Name Me!";
     public string Description = "Write Description.";
     public Texture2D Icon;
 
     public int Duribility = 100;
     public int Damage = 10;
     public int Armor = 10;
 
     public int Id = 0;
     public bool equipped;
 
     public Item itemtype;
     public Value value;
 
     // Use this for initialization
     void ApplyStats () {
         if(equipped == true) {
 
         }
         else {
 
         }
     }
 
 }
 
 
 public enum Item {
     Weapon,
     Helmet,
     Shoulders,
     Chest,
     Pants,
     Boots,
     Gloves,
     Item
 }
 
 public enum Value {
     Junk,
     Uncommon,
     Common,
     Rare,
     Epic
 }

And my Editor Code:

 using UnityEngine;
 using UnityEditor;
 using System;
 using System.Collections.Generic;
 
 [Serializable]
 public class ItemManager : EditorWindow {
 
     [SerializeField]
     private List<ItemClass> mast_items = new List<ItemClass>();
 
     // Add menu named "My Window" to the Window menu
     [MenuItem ("Window/Item Manager")]
     static void Init () {
         // Get existing open window or if none, make a new one:
         ItemManager window = (ItemManager)EditorWindow.GetWindow (typeof (ItemManager));
     }
     
     void OnGUI () {
         GUILayout.Label ("Item Master List:", EditorStyles.boldLabel);
     
         for (int i = 0; i < mast_items.Count; i++) 
         {
             mast_items[i].expanded = EditorGUILayout.Foldout(mast_items[i].expanded, mast_items[i].ItemName);
         }
 
         if (GUILayout.Button ("Add Base"))
             mast_items.Add (new ItemClass());
 
     }
 }