Updating levels.

I took a long break from making levels, and finally made one recently. All my levels before this latest one were made before the red coins update, and a lot of them were before checkpoints. Some of my old levels could use updating with checkpoints, keys, red coins, etc, but I'm not sure if I should upload new versions and delete the old ones, or keep the old ones around. I'm not sure I want to lose the history of those levels. I know I'll keep my star total, but some part of me doesn't want to delete them. What does everyone here do in regards to updating levels?