Mirrored this hook https://www.printables.com/model/410611-wall-hook to make it double sided and stuck it to the 9mm big thread t-bolt for the multiboard for the strongest possible part. 

I then sliced it in halfs to be printed without supports. If you want, you can glue the halves together, but I don't find it necessary. 

Remixed in tinkercad. I would like a nicer version somewhere down the line, but I am new to all this.