Rarity of 100% OEM Restored A Bodies - Rant/Whine

I like both myself. I find it a challenge to get an A body as close to factory as reasonably possible. Learning what goes where, how things are positioned or optioned and what color or plating a part should have. I can also appreciate the other. I was at a car show and someone had a stock 1970 Duster with patina, took out the six and put in a 360 with some old school slot mags and a tach on the dash and it was so cool. Brought me back to how they were back in the 70's and early 80's.