The old rubber cushions were almost completely worn out. I found one on eBay but decided to make my own. Using the old ones and photos from eBay, I created this part in my CAD system:

The part I made:

Please feel free to download the STL file:

You need to 3D print it using a rubber-like resin. Use a heat gun to warm up the part before mounting. This will make the rubber part soft and easy to install.

3D printed cushion: