Desktop stand for two Campus notebooks

I usually have two notebooks in active use at a time normally laying flat on my desk. But since switching from the relatively bulky Leuchtturm notebooks to the svelte Campus notebooks I realized I could easily create a stand hold them vertically in order to clear up some desk space.

I added a bit of heft by embedding some weights in the base of the stand. The 3MF file has a pause at the appropriate place to insert the weights (7). It also includes a brim to improve adhesion for this tall and thin model. I printed in Prusament Galaxy Black.  

The weights I used are from Amazon. Anything similar would work.  https://www.amazon.com/gp/product/B07RR14HKQ/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1

The Kokuyo Campus notebooks I use are “semi B5” https://www.jetpens.com/Kokuyo-Campus-Notebook-Semi-B5-Dotted-6-mm-Rule-Pack-of-5-Black-Colors/pd/30250