Hi Tim,
Do the wings on your emergers and spinners survive the magnetic pull? I'm serious, I've had lids in other boxes crush some of my dry fly wings to the point I couldn't make they look right anymore.
I use Myran 18 compartment boxes for most of my small emerges and spinners because I don't like crushed flies. I have used the Angler's Image boxes for some patterns in the #14 - #16 range. These are attractors: