Diameter and Radius
To most mortals, diameters of 2700-2710 km are close enough to a radius of 1353.4 ± 9 km.
Of course, in your business it REALLY matters if the surface of the planet comes up a little too high as you swoop in for the aerocapture!
As for the why of the historical changes, it probably all boils down to albedo. The modern value recognises a higher albedo, so a smaller body to give the same integrated reflectance.