Hey ft,
A point for discussion: You may have some rights to your scans, but probably not for the reasons you think you do. For example, just because you own the book, you don't have any inalienable rights to photographs of it. The creator of the book holds those rights. Your scans, are of course "photographs" of the book, which you created and therefore, you have copyrights to those photographs. Arguably, they are junior, derivative rights to the creator of the book. One might argue that you actually need permission from the creator of the book to publish your photographs.
Either way you slice it, even if you have copyrights, you have no means of enforcing your copyrights, or to enjoin others from using your scans, unless you take steps to register the copyright of the photographs with the Copyright Office. And, if someone actually made the scans for you, as in a "work for hire" the issue is even complicated further. For example, the scans CGC provides with its grading service are technically "works for hire" with CGC being the author of the scans.