I started unmounting my wheels years ago. I saw a blog post with the "how to" and knew I just had to do this since I was running out of room.
Inky Dinky Doo: Unmounting your Wheels - tutorial
I keep mine in a storage box and had 2 acrylic blocks made at the local glass shop.
I too write the name on the back of the rubber - I can't remember by looking at them!
I also don't use ez-mount. I use double sided tape - rubber directly on the acrylic block - but I do use a "place mat" which is a piece of fun foam to cushion it.