How do I make a Skinned Mesh Renderer independent?

Working on a character creator mechanism in which I can replace an existing full character mesh with multiple character mesh pieces.

The problem that I have right now is that when I destroy or hide the original character mesh, the added skinned mesh renderers stop animating - because they are still accessing data from that mesh.

I found the functional code in another thread, but I'm trying to do something different here. Can anyone suggest how I can properly separate the necessary data?

The script is attached to a separate game object which references both source and target objects:

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 using System.Linq;
 
 public class createMesh1 : MonoBehaviour {
 
     public SkinnedMeshRenderer sourceRenderer;
     public SkinnedMeshRenderer[] newItemRenderers;
     public int currNewItem;
     public Material skinMat;
 
     public void NewItem()
     {
         currNewItem++;
         if(currNewItem > newItemRenderers.Length-1)
         {
             currNewItem = 0;
         }
         ChangeMesh();
     }
 
     void ChangeMesh()
     {
         Dictionary<string, Transform> boneMap = new Dictionary<string, Transform>();
 
         foreach (Transform bone in sourceRenderer.bones)
         {
             boneMap[bone.name] = bone;
         }
 
         Transform[] boneArray = newItemRenderers[currNewItem].bones;
         for (int idx = 0; idx < boneArray.Length; ++idx)
         {
             string boneName = boneArray[idx].name;
             if (false == boneMap.TryGetValue(boneName, out boneArray[idx]))
             {
                 Debug.LogError("failed to get bone: " + boneName);
                 Debug.Break();
             }
         }
 
         GameObject newObj = new GameObject("addedGO");
         newObj.AddComponent<SkinnedMeshRenderer>();
         SkinnedMeshRenderer objSMR = newObj.GetComponent<SkinnedMeshRenderer>();
         objSMR.sharedMesh = newItemRenderers[currNewItem].sharedMesh;
         objSMR.bones = boneArray;
         objSMR.material = skinMat;
         newObj.transform.position = sourceRenderer.gameObject.transform.position;
         newObj.transform.parent = transform.parent;
 
     }
 }