I need 3 measurements, to the nearest 1/8 in.
The following photos will show you how to place the ruler to do so.
First I need the height of the case, when it is closed. Since French style cases are rounded, I put a business, or index card on top of the case and see where it intersects a ruler standing next to the case.
For the next 2 measurements, I open the case.
In this photo, I measure from the center of the leather hinge, to the front edge of the case, you do not need to include the depth of the latches in your measurement.
In this last photo, I measure the length of the case, from one end to the the other. All of these measurements should be to the nearest 1/8 in. Basically, if you are between 1/8 in. measurements, round up to the next 1/8 in.