As I said in my Ben Casey post, writer Carl Memling's ambulance sirens go "Rowrrr." When I saw that Nodel had drawn Emergency Doctor and that its sirens went "Rowrrr," my first thought was that Charlton had acquired an unused Ben Casey and had Nodel lightly redraw Vince Edwards' likeness. But the lettering in the Charlton machine style shows that this wasn't a Dell job changed with no more than a few brush strokes.
In fact, the script is by Joe Gill. He uses "Rowrrr" elsewhere for animal roars; by coincidence he uses it for sirens here. Did he rewrite Dell pages, which were then relettered? I don't think so; the number of pages in the issue's two Emergency Doctor stories don't match the fuller-length no-ads Dell standard. More tellingly, Emergency Doctor, along the lines of the nurse books, concentrates on an ongoing doctor-nurse romance that isn't in the Ben Casey comic because it isn't in the TV show.
Speaking of Joe Gill, from what I've seen he did write the vast majority of Charlton stories in the early Sixties. (Carl Wessler had written there in the Fifties, and the newbies like Dave Kaler, Steve Skeates, and so on, would come aboard in the mid-Sixties. I think Pete Morisi was writing his own stories before the mid-Sixties; I don't know Don Segall's tenure.)
One of Gill's stylistic tells is his long introductory blurbs with a number of sentences strung together with conjunctions. It seems counter-productive, when he was getting paid by the page, not by the word, but my theory is that it actually helped him in the long run. Joe Gill has said that he plotted as he typed (at his page rate, he had to). Getting started on the script with a flow-of-consciousness description of the set-up may have been a way of jump-starting the plotting process, to keep his mind a panel or two ahead of his fingers.