But they did wax the airframes, at least during WWII they did on the not painted Jugs and Mustangs. I do a fair bit of reading and the hot pilots usually include a bit about how the ground crew cared so much for the pilots' safety that they would carefully fill or or make flush blemishes with wax, then wax coat overall, in an effort to squeeze a few extra knots out of the plane by making it a little more aerodynamic then maybe the next guy. There's no way this wouldn't shine the airframe up considerably. Now, this may have been only in WWII, as I have only read a handful of books by Korean War veterans; by the time Mustangs and Jugs went shiny the USAAF had around a 5 to 1 numerical advantage over enemy fighters should they come across them, and being seen really didn't matter, and may have even carried a certain degree of intimidation while displaying said numerical advantage by just being there.
I personally think the middle of the road finish is the best looking on the Sabres as well, although I will fly any of them since the plane is just so dang sexy!