I bought this case off eBay:
https://www.ebay.com/itm/Aluminum-Open-Air-Frame-Mining-Miner-Rig-Case-For-6-GPU-ETH-BTC-Ethereum-ZCash-/312006948420

Some larger pics:
https://i.ebayimg.com/images/g/l9kAAOSwUoNaElWS/s-l1600.jpg
https://i.ebayimg.com/images/g/cFoAAOSwqbxaElWR/s-l1600.jpg

But I can't figure out how the mobo is mounted. It almost looks like there's a black string or cable holding it up? Any thoughts? I was considering screwing some wood pieces to the frame and then mounting the mobo on top of them.

Would appreciate any insight