Of the three, it's the birch ply that works the best and I especially like the plinth - great idea to cut it out of the core. My feeling about the London Plane is that rustic pieces of wood, with natural voids, doesn't lend itself well to precision pieces such as this. Most three-sided pieces look light and airy, but the weight of the wood and the indelicacy of its features fights against that concelt.
Les