A new better design is now available here:
https://www.youmagine.com/designs/leg-replacement-and-extension-for-cherry-kc-1000-keyboard
This extension clip extends keyboard legs by 2 cm, to increase inclination of a keyboard.
It fits tightly to the legs and clips into place, so it doesn't fall off by itself.
Keyboard still remains supported by its front rubber pads, so it doesn't slide.
If it saved your keyboard you can tip me here here: https://paypal.me/ZigaM3
I also design on redbubble: https://www.redbubble.com/people/reintegration/shop