The original box is amazing and sophisticated. However, the detail on the model makes it difficult to resize. So I totally redesign it in Fusion 360 with the same latch and hinge.
My cards (also 3D printed) are in the size of 86x54 mm.
The picture I shows is a two color print with my personal requirement. The model I provide is single color one.
Update: 2024.6.28. A 95.4x55.5 version is added, the largest standard business card due to https://www.brandly.com/blog/standard-business-card-size/