An interesting episode, especially as the 'American' Clarke came from Somerset, which is where my Clark(e)s came from ... and I noted there was an Edwin Clarke mentioned early on ... I too have an Edwin Clarke !
I must look into this line a bit more !!
I too wondered if there were descendents of the slave 'mistress' that Seb might have met ... he seemed embarrassed to hear this forebears were slave owners ... would have been good to have seen his reaction to meeting one of the distant Jamaican cousins