I really wanted a modular shelf to display my minis. This shelf is based around a mounting block, with parts that stem off of it. The connector rods vary from 10 mm for a flush join or a 20 mm rod for a more "modern" style. The 20 mm rods have a bump out that will keep the join flush with the body of the shelf pieces. Do not try to push this bump past.

The rods are also the same diameter as the hole with chamfer edges. This allows you to start it and then using force alone, push the rods in place. No glue needed.

The shelf includes a small indent to securely hold the minis.

I would recommend against using one mounting point. Rather I would do 5 at minimum. One for the center and 4 for the corners.