Default style overwritten - 3.8.4

[Zylantex]

While developing a new style for the forum we modified the default style and CSS. In hindsight it was not our cleverest move but it was a part of the learning curve. Now when we try to create a new style from scratch instead of it being based on the vanilla vBulletin default style it is based on our current style. Is there any way we can upload a copy of the original style and CSS files without over-writing our current live style? We have already exported / downloaded a copy of our current style as a precaution.

Thanks.