My '60 F100's paint code is "special." I know this was a Coke truck. Any way to find its original color...other than to sand it down. I used some lacquer thinner and steel wool and got to the second primer. I'm afraid to be more aggressive. With the original Coke logos to work from, the truck has (I think) long lasting value. Without that, I might as well buy a running '60 F100 and bolt the Serial Number plate to the glove box, attach the only bright work the methheads didn't steal and say "restored!"
i would think that if it was a true Coke truck then it would be the same Coke red that they used on everything Coke related, like coolers, signs, vending machines and all their delivery trucks in 1960.
Check with your local paint supply house, i bet they have that color listed as Coke items are hot items to restore these days and have to have the correct shade of red to be of any value.
I would think you could see the original paint color on the firewall or maybe the dash or inside the doors etc. Maybe pull back a weatherstrip just a bit and take a peek. It seems I remember some old Coke trucks from back in the 60's in my area were painted white and had red Coke logos.