So I did a little research on this to make sure I knew what I was posting about. This is still rough folks.
From the original post, I should have told the vbulletin member to use history. Your first modification of a template, stores the default (template master) in the history stack.
1. In all cases this works, but in the master style it does not append the correct template version. It does work correctly in any user styles. [Minor Bug].
2. 'Default' in all cases refers to the current master style, not the original style in 'vbulletin-style.xml' or histoy stack[0].
3. The history stack[0] automatic entry should be equivalent to 'vbulletin-style.xml' or the original master style for a template.a. This may not be true if you try to upload a new master style. I did not check this.
Example:
I accidentally edited a template in the master style. So in 'master style' I press 'Revert', to go back to the 'original' untouched master style template -- the same template that should reside in 'vbulletin-style.xml'.
BOOM! - This will delete the master template from the database. [Bug]. So don't press 'Revert' in the 'Master Style'.
Instead press 'History' and compare with 'History Stack[0]' -- the first history position stored.
Example:
My master template styles have been modified from the vbulletin originals. In the new style that I have created, on a particular template, it turned out to be an abomination. (I know this has never happen to anyone.)** So I press 'Show Default', which shows me the current master template: so I can compare.
This shows you the current 'default' master template. This does not show you vbulletin's 'original' template. This works correctly, in my opinion.
To see the 'original' template use 'History'.Update: This is not always true, in nested children styles: 'History Stack[0] will resolve to the 'default' master template. My wish is that it would have appended the 'original' template in the history stack.
** We are not discussing weather my period should be inside or outside of the parenthetical marks. 
Summery:
1.) Use 'Show Default' to compare to the current master template. 'View Original on 'controls block' works the same as 'Show Default' on template editor page, in all cases.
2.) Unless you save an 'original' master template in the history stack, you cannot be assured that a 'Original' compare version will be there.
3.) Do not try to revert a template in 'Master Style', you will delete the template.
Thank you: @Lynne, @Digital_Jedi, @ForceHSS, @Simon_Lloyd