There was discussion on the CLC Forum about the Bill Hirsch vs Seymour Cadillac Blue and I ordered 3 cans of the Seymour paint and did a side by side paint test today in nice sunny, low humidity, no wind weather using both paints.
Either I ordered the wrong paint or in my eyes the Seymour paint is way off as it is quite a bit lighter and more blue-blue than the original paint.
For the test I used two primed engine valley covers. The one on the left was painted with Bill Hirsch 1949-1976 Cadillac Blue and the one on the right was painted with the Seymour 98-53 Cadillac Blue paint.
Looking at the example original piece (the extended compressor arm of the cylinder head outlet pipe that usually runs considerable cooler than the core block) below the first side by side comparison picture, the original color was darker and had a tinge of teal (blue green) in the color. The Seymour paint also seems much thinner and believe it would definitely run easier if painting valve covers or other parts with vertical sections.
For those that think the Seymour is close that's your prerogative but I feel I've just wasted $40 on 3 cans of this stuff. For anyone that wants a deal on the Seymour paint email me at firstname.lastname@example.org and will sell all 3 cans including 2 new ones and one only used enough to apply 2 coats to valley cover for $15 + s/h.