I knew the second that I saw them and wanted them, that I was going to have a problem with identification...
Two very nice fridge boxes in pressed glass. They stack very nicely without any rough edges, and on close inspection, they are actually very carefully designed.
I've seen boxes by Wagenfeld (Kubusgeschirr) in books and know that Copier also made something similar for Leerdam, but there are (as you've guessed) no marks of any type on the boxes.
These two examples are 180x90x90 each which indicates they may be part of a mulit-box system.
How can I identify the different products from such tiny differences in design?