7" eleduino touch screen holder 2020

This is a mount for a 7 inch Eleduino(1024x600) touchscreen raspberry pi3 combo. Made to bolt to the top of a printer with 2020 extrusions. My First Ever design so any input is helpful. Itis just wide enough for exact sized bolts but for the rest i left some room(by accident) for foam padding

link to product:
https://www.amazon.ca/Eleduino-Raspberry-Integrated-Computer-LCD%EF%BC%881024/dp/B01DD5J612/ref=sr_1_sc_2?ie=UTF8&qid=1480550966&sr=8-2-spell&keywords=elediuno