I remember years ago working on a 57 chev belair restoration. Owner wanted 100% original. The paint was going to be done in tropical turquois. It was originally that color. The paint color on the car was 5 different shades of TT depending where you got it, ie trunk firewall fender hood etc. Talked to a really good friend that has been restoring chevs for a long time and he said across all assembly plants I believe 12 or 13 of them the only thing the same was the name of the color. It varied from batch to batch assembly place to assembly place. Take it for what it is worth. We quickly got over the headache of finding the correct TT, a fruitless task.

1953 Chevrolet 3100
261 cu inch, sm420, 3.55 rear, torque tube still,omaha orange, still 6 volt, RPO green glass, side carrier spare, all done
In the DITY Gallery
Video of the 261 running

1964 GMC 1000
305 Big Block V6, sm420, the next cab off restoration