Letter 68 and its response does not appear in the Brabourne edition of the letters. I have linked a PDF of this correspondence below.

In this letter, Jane Austen, writes to Crosby & Co. as Mrs. Ashton Dennis (MAD), regarding the MS Susan (later published at Northanger Abbey) which they bought for £10 six years earlier. The author requests immediate publication or else proposes to take the MS elsewhere to be published.

The Mr. Seymour referred to in the letter is William Seymour, Henry Austen's lawyer.