Restoring accidentally deleted content type
If a content type has been deleted, possibly all content of that type have lost their type setting, and so even if the content type is recreated, they might not be recognized as belonging to that type.

This should go without saying, but clearly that's not the case. Take a backup, before you happen to make things even worse.

You'll need to manually update the type column of the node table to the machine name of the content type.