The KIM-1 keyboard is a special one. Made especially for the KIM-1, as you can see in the SST switch. It shows its age in the design, and looks quite familiar to the keyboards hand-held calculators of the 70ties.
In those days replacement keyboards could be bought. I have repaired several KIM-1s with it. The older revisions were worse than what appeared on later revisions.\
Read this page how to repair some common problems.