I think the original film of "The Night Stalker" represents DC's original vision of how he would have liked the vampire on DS to have been. Since that movie was a huge hit and may even have been nominated for an Emmy (I honestly can't recall), there's no disrespect in stating this. The vampire on "Stalker" does seem a lot closer to the image conjured up by the material I have read over the years about how Dan wanted the vampire on DS to be. The reason why he did not wind up having more personal input on the original realization of Barnabas is that he was in England for some months in the late Winter and Spring of 1967, so the writers, for once, were left to do their own thing.
Writing the above, I wonder whether the way Tom Jennings was portrayed in the 1968 storyline showed some of Dan's influence. I don't know how closely he was keeping tabs on the show at that time. The hairpin twists and turns of the storyline during that period, to me, has Dan's name written all over it.
G.