The problem Richard, is that the face of that snake looks to be a sirtalis... I really don't think it's an ordinoes now that I zoomed in on the face. The face says sirtalis! And yes it could be a puget lacking laterals. I didn't catch where the OP was from. But I have seen concinnus with blue marked necks and black heads like that... But if the locality calls for puget, it Probably is!