How-to-make-GUI-Buttons-on-GUI-Texture-resolution-independent

Hello everyone. I am newbie to Unity and Android developent, and I am in need of your help to make my GUI controls resolution independent.I have posted the same question on the Android development forum, but I got not responce, so I am posting here with code, for better.

I have a GUI Texture in my scene to be used as a graphical background for a controller, and above this, a set of GUI buttons is rendered in absolute x,y screen positions. Those two elements rendered together makes the buttons controller for my android application, in a 480x320 HVGA Landscape screen resolution(see image 1):

The problem is that if the resolution is changed to 800x480 WVGA Landscape, everything is meshed up as you can see in the following screenshot:

I have tryed to make use of the Matrix4x4 to keep the GUI buttons scaled to a new resolution, but I still get them scattered all around screen.

Could anyone be kind enough to give some advise or maybe a code snippet on how to make both GUI buttons on absolute possitions and GUI Texture, screen resolution independent?

These is the script for rendering the GUIButtons above GUITexture:

 using UnityEngine;
     using System.Collections;
     
     public class GUIButtons : MonoBehaviour {
         
         public Texture btnTexture1;
         public Texture btnTexture2;
         public Texture btnTexture3;
         public Texture btnTexture4;
         public Texture btnTexture5;
         public Texture btnTexture6;
         public Texture btnTexture7;
         public Texture btnTexture8;
         
         
           void OnGUI()
             {
             
             if (!btnTexture1) {
                 Debug.LogError("Please assign a texture on the inspector");
                 return;
             }
                  GUI.Button(new Rect(68, 219, 50, 35), "");
             
             if (!btnTexture2) {
                 Debug.LogError("Please assign a texture on the inspector");
                 return;
             }
                 
             GUI.Button(new Rect(130, 219, 50, 35), "");
             
             if (!btnTexture3) {
                 Debug.LogError("Please assign a texture on the inspector");
                 return;
             }
             GUI.Button(new Rect(68,262,50,35), "");
             
             if (!btnTexture4) {
                 Debug.LogError("Please assign a texture on the inspector");
                 return;
             }
                 GUI.Button(new Rect(305, 219, 50, 35), "");
             
             if (!btnTexture5) {
                 Debug.LogError("Please assign a texture on the inspector");
                 return;
             }
                 GUI.RepeatButton(new Rect(366, 219, 50, 35), "");
                     
             
             if (!btnTexture6) {
                 Debug.LogError("Please assign a texture on the inspector");
                 return;
             }
                 GUI.RepeatButton(new Rect(130,262,50,35), "");
             
             if (!btnTexture7) {
                 Debug.LogError("Please assign a texture on the inspector");
                 return;
             }
                 GUI.Button(new Rect(305, 262, 50, 35), "");
             
             if (!btnTexture8) {
                 Debug.LogError("Please assign a texture on the inspector");
                 return;
             }
                 GUI.RepeatButton(new Rect(366, 262, 50, 35), "");
             
         }
     }

 

Thank you all in advance for your answers.