Or maybe Photoshop the levels to look like Roman numerals?!
I would like the center to feature these kinds of raised symbols (the symbol of knowledge from the apprentice's book, the mana charm from the novice's book, the negativity charm would look quite harmonious on the wizard's book, and a protruding crown of the archmage in the center of the archmage's grimoire).
That would be ideal. Perhaps in the future, I'll find an artist who can do that (probably for money).