change blog id, url

We are using serveral blogs. Since we have been using WordPress for many years, new blogs have been created and old ones deleted. We wanted a private blog to hold a exact backup of one blog’s posts, so I copied those database tables to a newly created blog. After that I realised I copied the options table as well – mistake. But I also changed the url, and other things for difference.
About a week later I realised that when I viewed all my blogs (Dashboard -> My Sites [~/wp-admin/my-sites.php]), the copied blog name appeared in place of the original. How can I get it back?
Previously I copied and manipulated the database to create a local version, modified some of the .php files to contain custom code and merged plug code, but I cannot find where the problem is. I’ve looked at the wp_blogs, site, sitemeta and even the blog options tables, but because there is so many blogs I can’t see the cause. Please help.