iWeb uses a domain.sites2 file to store its assets.
It's here :
~/Library/Application Support/iWeb/
where ~ is your Home Directory.
Here's an easy way to find out :
http://wyodor.byethost8.com/iwebsites/iWebSites.html
If you open iWeb and the file is still there, you can use it to publish to a folder or to a remote server wih FTP.
If the file is not there and you haven't a backup, then you'll have to start from scratch.
Since MMe ceased to exist years ago, your published website is gone. You may remember that you got mail to announce that.
You can still use iWeb. Or use another application to create webpages.
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