So back here, I bemoaned the discovery of a print I really liked, followed quickly by my discovery that it seemed to be ubiquitous.
With so many "Keep Calm and Keep Going" posters out there, I did not expect to receive a reply from the artist currently creating some of the prints. But I did get a reply - and I got schooled! The artist informed me that he hand-lettered his reproduction (as the original was hand-done) and then cleaned things up on the computer. He also refined the art in his own unique way, so that there is something of himself in it (and so he can bust anyone who copies him - clever). Mr. Papermoth was also kind enough to send me a link to a telegraph article which provides more info on the original bookseller/poster-finder, Barter Books.
The conversation restored my "consumer confidence" (and taught me to be a little more patient), and now I can happily order myself a print, feeling satisfied that the artist selling it has integrity and approaches his work with care.