JA wrote; 'I have set down Mr Jeferson's case to Edward, and he desires to have his name set down for a guinea...; but does not wish for more than one copy of the work'. Letter 52, dated June 15. 1808

This reference was to works of Revd.T. Jefferson of Tunbridge, Two Sermons (1808); the list of subscribers includes Mr & Mrs Edward Austen of Godmersham and Miss Jane Austen.
Notes to Letters. no. 12. Letter 52. D. Le Faye editon of Jane Austen's Letters p.388.

I think this Mr Jefferson and being down as a subscriber to his works; JA refers to in Letter 54, dated Sunday June 26.