While many are indeed over restored it's easy to understand why. 1 person is deciding the quality of fit and finish on every component. Each gets that person's full attention either by direction to the shop/techs doing the work or from their own hand. Who would intentionally slop the finish on in select places? I have to be honest here, I would when the time comes. 10 yrs ago I did some intentional "quicky" work under a 68 GT 350 conv. I had red oxide underneath on the floors and subrails, when it was time to paint I purposely held the gun in a fashion to get uneven color here and there. As a finish, just as it was when new, I hastily sprayed semi-flat black on the rocker panel pinch welds letting just enough get on the red below as well. In all fairness the car was so intact and unmolested it was just short of a privilege to restore it.
Having worked at a GM gear and axle plant, the black paint was really a short term stop-gap measure. Most of the full housings were stored outdoors and got a healthy amount of surface rust when bare. I never did get to go to the plant where they got painted as I was in the gear manufacturing bldg. So what should you do? 1st, whatever YOU want to see or would direct your workers to do. 2nd, go ahead and paint the whole thing but don't worry about getting it as nice as a fender. That does look fake, overdone. Get a run or 2 where it can be seen if one were to look for it, but perhaps not too evident. If you do go in for high point OEM grade judging they can't knock you for excess quality as long as a run or 2 or 6 are evident, even if you must point it out to the judges.
I agree with the concept that most exponentially exceed OEM standards, but in a sense they almost have to. Would you spend the full value of a car in restoration, only to have it rust and deteriorate just as soon as they did in their heydays? Balance can be achieved during the process, flat clears go a long way, but priming and blocking of frames and mechanical parts should be tempered with an eye toward REAL. I also feel sad for owners of some of the 30s heavy cars with cut and polished frames. They were robbed of their $$$$ in shop rate to do what was never done. Not even on the mighty Duesenberg. Perspective and restraint goes a long way. Embrace the challenge.