Sure, you could use a small desktop mill to make aluminum molds for plastic injection, and produce them (slowly) with a relatively inexpensive miniature plastic injection machine. The main issue I foresee is getting the recessed numbers to release. You would either have to draft them significantly toward the parting line of a two-piece mold, or make a mother mold which would hold multiple pieces that would pull off separately, then be reassembled before the next shot.
Alternatively, you could machine the positive dice, make rubber molds from them, and cast them using a 2-part liquid epoxy, urethane, or polyester resin.