[AequitasOmnibus]

The stories may be public domain but your arrangement, and more importantly your trade name are protected. You may not have the desire to take action like a dmca takedown, but you're definitely within your rights to do so.

[thaumasiotes]

You can stop the third-party vendor from saying "I am Standard Ebooks", but you can't stop them from referring to the book as coming from Standard Ebooks, because that's true.