printed with 3 walls and 35% infill. at 60mm/s this print takes roughly 45 minutes at 0.15 layer height. the print is designed with a slight taper on the faces that meet the coin and the diameter is slightly undersized to apply pressure to the coin, do not scale the model up or the coin will be loose. 

when wall mounted the coin will sit at a slight angle on the wall,  you can spin the mount 180 to invert the angle.