stuart in mn MegaDork
5/2/24 6:08 a.m.First generation Mustang guys have approached the Corvette guys when it comes to restoration accuracy - one thing about Fords is they seemed to stamp a date code on just about every little component; I have a friend who's big into Mustangs and I've spent a lot of time at swap meets with him where he was looking for radiator caps or other minor parts that had the correct date code for his cars. There are also certain GM cars (like late 60s GTOs, Chevelles, etc.) where the factory assembly manuals are available which helps a lot.
For most cars you have to rely on what others have figured out or from examining low mileage examples. I have a 1961 Pontiac Bonneville; I also have a full set of shop manuals, a parts catalog, dealer update newsletters, etc. which helped but you can't tell exact paint colors or finishes from small black and white photos in a 60 year old book.