Yes. Handmade from scratch. No special electical hardware other than jigsaw and powerdrill.
you could easily sell those man
Im going to make second one soon and i will probably sell it on auction when its ready. Not just case, but complete miner with 4x 280x inside. This one is going to be better finished than my first prototype. I will probably paint it black before assembling.
I will also add high quality pictures when its ready.

Great job. And You´re lucky guy, if there are 4x R9 280X available in Your country. There is not even single one in my whole country - everything is sold out for next 3 weeks