Of course, there are many translations of the Brothers Grimm in English, so I am not going to worry too much about the oddness of the Project Gutenberg edition. The main thing is that all the stories in the Gutenberg edition are available at LibriVox for your listening pleasure! You can also consult books by Marian Edwardes and by Edgar Taylor online as follows:
Fairy Tales by the Brothers Grimm, translated by Edgar Taylor and Marian Edwardes, with illustrations by R. Anning Bell (1912). Available at Wikisource. The stories from Edwardes appear to be the following: The Frog Prince, Briar Rose, and The Mouse, The Bird, and The Sausage.
Grimm's Goblins: Grimm's Household Stories, translated by E. Taylor, with illustrations by George Cruikshank (1876). Available at Internet Archive.
(See also the edition published under the title German Popular Stories, also available at Internet Archive.)
You can find additional online editions of the Brothers Grimm in English at Dan Ashliman's very helpful bibliography of online editions of Brothers Grimm in English (although he does not include the Marian Edwardes book, which is oddly hard to find; the Wikisource version is the only one I know).
If you are doing research on Brothers Grimm, the English translation online that I would recommend you consult is by Dan Ashliman! It is not complete, but it does have all the most famous of the stories, and it is the most reliable edition you will find online: The Grimm Brothers' Children's and Household Tales.