Judging competition cars

How does AACA judge competition cars? By their nature, these vehicles undergo multiple engine swaps and body mods during their lives. Each vehicle is unique, so there's not a standard to judge against. I have seen some described as "restored to condition raced in the (year)(name of race)". Do exhibitors of such vehicles have to provide documentation, such as photos? Is a record maintained of which VIN's were raced at each race? If not, how does one document the provenance? Marque club registry?