I went for a variation of the perspex solution using MDF, hexagonal bolts and screws instead.
Holes are cut for easy access to the dip switches. PCBs can then be stacked neatly without risk of damage.
The best thing about this approach is they are freestanding, so I can place a few of them in the Egret II without having to attach them to anything and they don't touch each other or the cabinet.
You never need to actually remove them from their casing, antistatic bags and boxes are great for long term storage but once you remove them, you have to handle the boards and can accidently bash them about or static shock them. This approach offers full-time protection and you never touch the actual board.
I've stored most of them in our bedroom wardrobe, top shelf, nice and out of reach from children's prying hands! There are 3 double doors worth of PCBs
Does work out quite expensive per board though. I can't find a decent source of cheap hexagonal bolts.
I can't take credit for this idea though, I used a slight variation that vib_ribbon on Jamma+ came up with.