While reading a free ebook version of Tusculan Disputations, apparently photo-captured from a long-out-of-copyright edition, and being interested in the unusual grammar in the older book, I "flipped" to the front of the book to check the name of the translator:
A quick internet search for "a new translation by a gentleman" appears to return Tusculan Disputations as its top result. (And the other high results did not seem relevant.)
Was specifically attributing authorship or translation to "A Gentleman" an unusual thing in that period?
(It's difficult to know how to search for such an answer, since "A Gentleman" is a very generic phrase, and will largely return irrelevant results.)