Well, Schwalbe also calls them 700C x 50, which is slightly smaller than 2". However, this is good information. Peatbog, even though your info isn't directly related to what I need, it's still good reference, it shows that size coming up wider than the designation. How close to 26" diameter are they? Really, someone should be putting all this in a database.
I'm looking at using a Varsity or Suburban frame as the basis for prewar, motorbike-style build. I want to put the FF's on it if they'll fit, and based on measuring a Varsity I have, it'll be close if they come up nominal based on the metric size. There's not much room for error, unless they do run small. I'd also like to be able to squeeze a set of VeloORANGE zepplin fenders in there too, but that would be real tight.