Rather than creating a list, it's far simpler to lift the unique book ID out of the URL for each of pages of the books you wish to combine, and then issuing a 'bookid:' search for each of those IDs.
Here's how to do it. Let's say you find two duplicate books, but you can't get them to appear on the same page. You need to get them to appear on the same page in order to get to the "If you see duplicate books, combine them" link.
First, you need to get the unique book ID for each book. When you're on the book page, you'll the see book URL is something like this:
See the number in the middle? That's the unique book ID. Make a note of it. Do this for as many books as you need to combine.
Next, issue a search using the special 'bookid:' keyword. Using the 'Search' bar on any page, search for the books by supplying a list of comma-separated IDs, like this:
On the search results page, you'll see the "If you see duplicate books, combine them" link. Click this, and get combining!
Thanks to starwolvie for the advice on searching by bookid.
Another option for the more technical folks is to construct a 'combine' URL which has the book IDs embedded in it in URL encoded format, like this:
(The book IDs in the example above are 1234 and 4321.) This will bring you straight to the Combine page,with a big fat COMBINE DUPLICATES button.