After you changed back and forth several themes, after tons of posts and some followers, you might wanna go back to Tumblr’s original Theme/Layout.
But how do you change back to Tumblr original theme?. Easy, since the theme is a featured design in the Theme Garden, you can just reinstall it, the original layout is called Redux. Also, you could create another blog and copy paste the unmodified html.
Tumblr Codes to Customize Your Theme
You can visit our section Tumblr Codes, if you want to tweak and fully customize your Tumblr Theme, cursors, link effects, backgrounds, and plenty of widgets.