I turn out to be wrong yet again. I knew that the F2H-3/4 tip tanks had a capacity of only 170 gallons compared to the -2's capacity of 220 gallons and therefore imagined that the -3/4 tanks were smaller. It sort of looks that way.
My guess is that the -3/4 tanks appear to be smaller because of the airplane's longer forward fuselage and tail cone and the increase in wing chord inboard of the fold line. However, I'm now all but certain that the tanks are the same size and shape. They are different, however. The -2 tank was mostly fuel; the -3/4 tank was comprised of what I'll call a capsule, with fairings added on the front and back, so it held less fuel. The only notable external difference was that it had prominent flanges and fewer filler caps/access panels.
Because it had more internal fuel and smaller capacity tip tanks, the F2H-3/4 was often seen without tip tanks. A smooth wing tip could also be installed in place of the one on which the tank was mounted.