Define Pages Editor V1.3.8a

[Wambat]

I'm going to upgrade, just as soon as I can get my customised pages sorted out.
What I can't figure out is what determines where the dropdown box in Admin for "Define Pages Editor" is set.
I see that it is listing the files in "includes/languages/english/html_includes", but my added on template are the files that are being used at the front end ..
includes/languages/english/html_includes/dezina_advent138.

I don't see that it is a part of the over ride system?
Do I just delete the add on template ones and use the standard directory?
Will it be overwritten in the upgrade?

[RescoCCC]

That is part of the overrides system.