space-saving storage system for Canon lenses

I desinged this storage system to put away my Canon lenses on top of my audio system in a space saving and accessible way. Since there is always some fluctuation in the lenses I use, the system has a modular design.
The lenses are hold by help of the original, slightly conical rear cap from Canon. Other caps, such as the beautiful (imho) but larger Sigma rear caps, won't fit. The lens holder element has two mounts for lenses, where the front mount is tilted slightly to shorten the element footp