Convert periodicals to books

Hi...

Kindle has the irritating behaviour that it won't allow you to move periodicals to folders as you can with books. The last edition of a periodical stays on the home page. This is ok until you cancel a subscription and are then stuck with the issue on the home page and can't archive it, or add to a collection.

I figured that as the periodicals came from Calibre, it should be possible to alter it to be treated as a book, not a periodical.. But i can't find anything in the meta info to allow that "conversion".. Any ideas how I can do this?

Thanks!