I'm sure you'll see his response and my own but for anyone else following this I wouldn't want to leave them hanging, but they'd never have any reason to place 20 unique symbols meant to be numbers on a single die, they might have cause to put 9 on one, two of each digit and a pair of blanks, to be used with another die but since they've 3 sets of 9 symbols, 27 symbols for 1-9, 10-90, and 100-900 there's really no reason to have mixtures of those three sets on the same die. You could use 3d10 (or d20 with repeats) each d10 with its own set of symbols, to generate any number between 0-999 with equal probability so long as you included a blank/null/zero symbol for the extra slot on the d10 or the 2 extra slots on a d20. But you'd never have a reason to mix sets.