Create an offset to adjust Quaternion rotation

Hi all, I use the following script to make the player rotate to look at the mouse position. However, my model needs to be rotated a little to compensate on a couple of animations so I would like to have a float offset that I can use to adjust the rotation either + / - its set value from the mouse position.

I have created a public float, I just cannot figure out how you apply it in the code that rotates the player model.

Here is the code, please can someone help me?

 using UnityEngine;
 using System.Collections;
 
 public class PlayerTurn : MonoBehaviour {
 
     Rigidbody playerRigidbody;
     int floorMask; 
     float camRayLength = 100f;
     public float offset = 0.0f;
 
     void Awake()
     {
         playerRigidbody = GetComponent<Rigidbody>();
         floorMask = LayerMask.GetMask("Floor");
     }
 
     void FixedUpdate () 
     
     {
         Turning();
     }
 
     void Turning()
     {
         Ray camRay = Camera.main.ScreenPointToRay(Input.mousePosition);
         RaycastHit floorHit;
         if (Physics.Raycast(camRay, out floorHit, camRayLength, floorMask))
         {
             Vector3 playerToMouse = floorHit.point - transform.position;
             playerToMouse.y = 0f;
             Quaternion newRotation = Quaternion.LookRotation(playerToMouse);
             playerRigidbody.MoveRotation(newRotation);
         }
     }
 }