In s3e17, Gaius Baltar demonstrates his original Aerilon accent to Chief. It's a gravelly "back of the throat" accent that sounds a lot like Mark Sheppard. Next episode we meet Baltar's lawyer, played by...Mark Sheppard. His law career is obviously on Caprica, but are the accents just coincidence? Is Lampkin faking it because he read the book? He doesn't strike me as a manual labor-type, but his story could be similar.