Router table: https://www.amazon.com/Goplus-Electric-Aluminum-Craftsman-Benchtop/dp/B01EUVRMNC/ref=sr_1_1_sspa
Round-over bit for the top. Straight bit for the box and notches. You'll need stops for the table to avoid cutting too far.
Hand file for the interior box corner if you need it sharp.
Probably take me a two hours for one, three hours for a dozen. But I'm slow.