One of the hardest to match! A friend had his '68Jr painted Bluette, under his dash pad was pristine paint, all of the paint samples were off and the shop had to mix a special blend to replicate the original untouched paint from under the pad. It touch months as the shop brought in different samples from different manufacturers. Good luck.
I used ATS Tower Paint in Wisconsin. They were spot on in the spray can they supplied but that was 501 Red, here is the example. I painted the horn bracket with the Tower spray paint after the car was painted I think it will be different for the Bluette, worth a shot. I think it cost me $20.