I would recommend either making an RTV mold or have one made for
you, I cast a line of collegiate logo charms and sorority charms for
a client that are quite small, and have a lot of detail.
I have had great luck using RTV Silicone rubber from Zero-D, I used
to be hesitant about RTV liquids but several of these molds have had
many hundreds of pieces injected in to them and the wax patterns are
still crisp and well detailed.
You will need access to a vacuum pump though as the molds need to be
de-aired (to get all the nasty little bubbles out), Usual
disclaimer, no connection to Zero-D other than a satisfied customer
Wishing I were in a warm sunny place (like Tucson)