Centering a symbol on a responsive stage

First, I am completly aware that many have posted about this...but after a good part of the day...I can not make it work...I am having some real dificulty in centering an object based on viewport.

I am surprised at how much of a challenge this has turned into

Very Simple proof of functionality...online here: http://www.mattabron.com/animate_test/

1. Isolated out simple functionality

2. Created a stage called 'test' @ 2600x470pxs (targeting HD monitors to tablet)

3. Set Stage to 100 percentage width

4. Added a simple shape called 'test1' > converted it to a symbol

5. Centered on stage

6. Changed Settings as per below

7. Added this into the creationComplete Code Window:

sym.$("test1").css({

   width : '2600px',

   margin : '0 auto',

   position: 'relative'

});

***THE RESULT: it is fine at 2600 viewport but for 1024 it does not center.

Here it is online: http://www.mattabron.com/animate_test/

THANKS FOR TAKING THE TIME TO HELP!