I've adjusted original MeArm files https://github.com/MeArm/MeArm in Fusion360 for 3D printing.
Screw holes are prepared for M2.5 screws.
MeArm Maker Kit can be bought here:
https://shop.mearm.com/products/mearm-maker-kit-cut-your-own
The arduino UNO shield can be bought here:
https://www.aliexpress.com/w/wholesale-Electronic-building-blocks-Dual-PS2-game-joystick-.html