Floats not being applied?

I'm very close on completing a script that allows the arms of my character to aim towards the camera. I used the last spine bone to apply the rotations to.

And here's the problem:

This is my hold animation with the chest slightly turned.

With script enabled:

The spine bone I assigned as the bone to rotate is instead facing the direction of the camera at all times. This offsets the position of the arms to the left.

I calculated the float value difference (x and y rotations) between the camera(or head/neck) and the spine bone when the animation is correctly displayed (script disabled) and I added it to my ArmControl script. Unfortunately, adding those float values are not making a difference when the script is enabled.

ArmControl (JavaScript):

 var spineBone : GameObject;
 var cameraObject : GameObject;
 var mountObject : GameObject;
 var spineX : float = 2.683764;
 var spineY : float = 5.290291;
 var spineXPose : float;
 var spineYPose : float;
 
 function LateUpdate () 
 {    
     if(GameObject.FindGameObjectWithTag("Player").GetComponent(PlayerMovement).weaponReady == true)
     {        
         spineXPose = mountObject.GetComponent(MouseLook).currentXRotation + spineX;
         spineYPose = mountObject.GetComponent(MouseLook).currentYRotation + spineY;
     
         spineBone.transform.rotation = Quaternion.Euler(spineXPose, spineYPose, 0);    
     }
 }

I'm also including my camera control script to help out with specific components I'm using:

 var lookSensitivity : float = 5;
 @HideInInspector
 var yRotation : float;
 @HideInInspector
 var xRotation : float;
 @HideInInspector
 var currentYRotation : float;
 @HideInInspector
 var currentXRotation : float;
 @HideInInspector
 var yRotationV : float;
 @HideInInspector
 var xRotationV : float;
 var lookSmoothDamp : float = 0.1;
 
 function Update()
 {
     yRotation += Input.GetAxis("Mouse X")*lookSensitivity;
     xRotation -= Input.GetAxis("Mouse Y")*lookSensitivity;
     
     xRotation = Mathf.Clamp(xRotation, -20, 35);
     
     currentXRotation = Mathf.SmoothDamp(currentXRotation, xRotation, xRotationV, lookSmoothDamp);
     currentYRotation = Mathf.SmoothDamp(currentYRotation, yRotation, yRotationV, lookSmoothDamp);
     
     transform.rotation = Quaternion.Euler(currentXRotation, currentYRotation,0);
 }