Hello! I think another category that might be useful is ephemera - various objects that are connected with pens and pen collecting. For example, I have an old brass ink well that is in the shape of an Egyptian Sphinx, where the head lifts up to expose the well. I also have a large Pelikan bird that holds a pen in its beak, and a Kaweco German Shepherd that also holds a pen in his mouth. Likewise, there are many different desk accessories and other items that could fit this category.
Yeah, there’s also pencils, a wishlist, and few others.
I do have that somewhere on my list of things to implement, but right now I just have enough time to keep the site running.