Eastman-Kodak 51 sheet film date?

Hello - can someone help me date this 8x10 negative? One v notch, edge printing "Eastman-Kodak 51." The original image is from 1929 ... guessing copy negative. I have the notch code list from Horvath's survey paper but there must be an online list of Kodak sheet film edge printing codes, can someone point me to it? Or is it just the number in the box?