There's a good picture of a closed Hudson staff car in the excellent (and essential if you're into WWI softskins) book 'The Observers Army Vehicle Directory to 1940' by Bart H Vanderveen. Unfortunately i'm now down in London for University so won't have access to a scanner for several months
Thank you, Rob. That is the beast in question. I was hoping that someone might know of pictures of the ambulance version as well as open and closed cars. I now have good chassis drawings of the Hudson six cylinder car. Incidentally, according to a biography, in his role as driver, Rickenbacker was recognised for his proficiency and competence at maintenance and repair whilst driving a Hudson. (There was some resistance to allowing him training as a pilot!)