I could not find an STL for a Roman Aes Grave coin so I used Meshy to create a rough design based on a real example and then modified it with Tinkercad. It is definitely not perfect, but it is dimensionally very similar. My intention was to do sand casting and make a bronze / brass version. This is a work in progress and I hope to improve on it in the future. Whether for educational or hobbyist purposes, I hope someone finds this useful!