This parametric stackable box lets you customize length, height, width, wall thickness, label space, and allows you to add a separator. Rather than put up with a re-scale from an existing model, you can now handcraft something to your liking.

This is designed to print well, and print easily.

To customize to your needs, you'll need a free OnShape account:

https://cad.onshape.com/documents/229e90b13638c8f480d547f8/w/d2c121169c1e5d440020262a/e/a67433e507bb5535b134ea0d

The model will probably have further adaptations. If you can think of something extra it might need, either make a copy or make a suggestion in the comments.