If that target is resin, then your new name is "castmaster".
The targets are indeed resin. They started with .005 sheet styrene parts cut on a Silhouette.

A master was made on a scrap of etched brass to help with alignment, and to make sure the slots opened up. I make a lot of them because not every one is usable, but I don't really know which ones are the best until after I make the mold and do a test casting.

Here are a few spare castings on my pinky finger. They're done in both N and Z.

The backsaver handle will be resin also; I'm getting a master lasered for me.