Hi, That looks like Zircon Blue, You may have to take the car or part of it to get the paint mixed. Paint formulas then and now are not comparable because of the different ways, weight Vs percentage. However be aware that there's a more modern Zircon Blue which is not the same. There's is also the possibility of getting yours spectrographed to produce a modern accurate formula, you may have to phone around for a supplier that will provide the service. Having said that a good mixer should be able to get close with the car present to check as he goes.
Colin