What is the absolutely correct blue engine paint color for a 74 Duster?

Even the toner the auto paint pro shop uses today can vary and doubt full is same as 50 years ago.
Someone my best (in my opinion) matches has come thru TCP global color library, but no doubt their toner might vary from year to year????
I understand wanting to do it "right" but let face it, but people will argue about Mopar engine blue till the cows come home!!:steering: