After much patient soldering (made worse because of OCD nature of yours truly), the LoL shield is finally up and running! These assembly instructions were superb, especially the video on how to straighten all the LEDs for maximum OCD-ness.
It doesn’t last super long on a 9V battery (unsurprisingly) but it was enough to help me advertise the Valentine Day’s edition of Bourn Fridays. On top of that, I now kind of know what “charlieplexing” means!