This video and Instructable give the steps to build a keyboard, video, mouse (KVM) that is also a Raspberry Pi Laptop. The display, keyboard, and touchpad from an old Dell D630 are repurposed to make a small lightweight KVM. The keyboard and touchpad are converted to USB by a Teensy microcontroller. A video converter card receives VGA and HDMI and drives the LCD.
The Instructable is at: https://www.instructables.com/id/DIY-Portable-KVM-Crashcart-From-Recycled-Laptop-Pr/
All of the files are located at my GitHub repository at: https://github.com/thedalles77/USB_Laptop_Keyboard_Controller
A complete parts list is included in the Instructable.
Hackaday covered this laptop at: https://hackaday.com/2019/03/10/from-a-dead-laptop-to-a-portable-kvm-and-pitop/