The built in Wordpress importer doesn't let one import a Blogger FTP blog. I tried converting my FTP blog to a Blogspot one, but that didn't help.
Luckily, a post by AlanA pointed me to Blogger2Wordpress conversion tool. I exported my blog from Blogger, uploaded it to the tool, it spat out a .wxr file which I then imported to Wordpress.
Looks like it has got all the posts, images and comments.
Great stuff.
I was struggling to do this, so decided to Google it. Your site with its link came up and it works like a dream. Many thanks. Mike