I've seen that called an Oval C on a couple of sites that discuss Fender profiles. Not sure if Fender officially calls it that, I think it's the same profile thy call the "mid-60s C" that you can find on the American Vintage '65 Strat. These also had more of a taper in thickness than modern Fender necks, i.e. the difference between the front-to-back thickness at the first fret vs at about the 12th fret.