I customized the print in Fusion 360. I used an English tupence coin. I paused at layer 31 to insert the coin. Had a little trouble with the initial layer, but that was mostly because of my printer, although the rounded edges are an issue. If I were to print again, I'd use 0.16 or 0.12 layer height instead of 0.20 because the rounded edges make the individual layers quite visible.