If necessity is the mother of invention, then broken parts are the mother of 3D uploads.

The included STLs are for three of the keyboards I had in my office.

And you should be able to customize the design for many other keyboards if you have calipers handy to measure the existing leg/foot.

OpenSCAD file is included for customization. If your leg/foot doesn't fit the design - let me know the details so I can update this model.
 

This will need supports for the arm knobs, and possibly for the rounded ends (depends on your printer and material).
 

So far ABS and ASA have been too soft.
PLA and PETG worked really well (7 years and counting).
Most SLA acrylic resins are too fragile, but some "tough" and "high tensile strength" resins have worked decently.