Reusing plant labels

Last two years, when I planted my seeds, I labelled my tomatoes T1, T2, T3... , Peppers P1, P2, P3... , Eggplants E1, E2 etc. I kept the equivalents on a spreadsheet that I made several copies of to put on the door of the greenhouse and other places. Of course the second year the equivalents were different.

I think this would work great if only I could find those labels to reuse.