[HarryT]

I'm afraid that the amount of effort you've put into something has no impact on its copyright status. If a work is in the public domain, it's in the public domain, and putting in a lot of work making it look nice won't change that. If you've added something original to your Shakespeare volume, such as an introduction, or footnotes, then those elements and those alone will be protected by copyright, but the actual text of the poems or plays will not be. So, if you want to prevent someone from copying your entire book, write a short introduction for it. That way nobody will (legally) be able to resell the book without your permission, although there'll be nothing to stop them from editing the book, removing the introduction, and then reselling it, of course.

You can upload a book to MR on whatever terms you wish, although if you claim copyright where no valid copyright exists (formatting isn't protected by copyright!), you'll have no valid claim against anyone who uses your book in a manner that displeases you.