Pantone color guides have been standard issue in the print shops I’ve worked in for the last 40 years. They are typically thrown away in 12 month intervals, as the color chips do change with time.
I am always happier with a refinish to a car, or, piece of equipment, when I repaint the whole thing. Matching an old color, with new, is more art than science, from what I have seen.
I’ve shot a bunch of paint with an old Binks #7, it is obsolete for newer materials, mostly due to the cost of the stuff, but, for an occasional small project (I’ll paint a 1941 Colson Scout when it warms up a bit) it is entirely adequate.