You can not have differences on hard facts which have been measured by professionals with equipment that is more expensive then the actually car today. Hard facts and numbers speed to decibel. Just accept it that both cars Corsa C + 454 have the same dB-Values on the asked 70mph speed. Especially if yourself have never done a 1:1 comparison with measurement equipment on both cars when they have been new and not after decades of wear and torture at street. Just think on old engine and transmission mounts how much they affect noise inside the car etc Or a 454 weak point when have been on bad conditions: Rust under the roof on the glue points, defective gum seals with electrical roof etc. There are so many points which affects inside noise while a car gets old. Nothing ever to compare with new delivery, realize that. 100% bet that a 16yrs old 454 (or same age Corsa C) in common hands will produce more then >71/72db @80mph like it has been measured when it was new. But that isnt gilty from the car, its shame from the owner.
Old and worn its too much words for writting with smartphone and not the same 'old and worn' audio system for example supposed that when you restore it, it will be good - but even new and not worn it will be still / have been crap. Crap is just one quick word and its nothing bad, its just crap or garbage no matter if 454 or Corsa C in our days or like asshole in greek is something which you are calling your friends or kurva mac in polska is just sh*t happens etc. Step over your local borders. Despite them i am the one who is defendig the 454 at this thread while telling that its not more worse then any other MiniCar from the same year while driving at 70mph.
Its just not a fat Jaguar/Benz/Bentley.
