I have a bunch (5 or 6, maybe a couple more) of empty 4x5 film boxes that you can have, but I am located in the U.S. and I am not sure if the shipping cost would be worthwhile (no charge for the empty boxes, of course!). I think it would be a good idea if fellow APUG members in Denmark or nearby have any to spare. If you don't find any locally, you can contact me.
If you are willing, I could use 2 or 3 boxes. I've just started out w/ LF and find that I need a place to keep exposed film until processing.