Probably not cost effective and no demand is probably why nobody makes them, wonder how many you'd have to sell to recover the cost???, be a cool deal to do though..

My son does 3D printing I'll ask him if that is feasible.  That said, it you resin cast from the original you get the DOT ID too. You might consider cutting down a lens from something larger. I find that a cut-off wheel and a grinder with light pressure cut plastic well. Cutting with a saw usually grabs and cracks the plastic.