Two different actors with the same name are credited for playing the same part. Neither has a picture.

Thank you for your prompt reply to my inquiry.  I must admit that I failed to notice that the first names were actually listed differently.  I first saw the numbers behind their names and just assumed, and we all know where that gets us.  I've attached a photo from ep 1.5 to better illustrate the particulars of this issue, and just to add to the confusion there is no one named Dave or David Arthur credited in this episode.  

Now that I've had a chance to review what I've written, and with deepest gratitude for your observation, I may just be able to solve this mystery all on my own.  Cheers, Mate!

Thanks again for getting back to me so quickly.