Passenger side lock button missing rubber

Just bought one of these for MIL.

The door lock button in the passenger side is missing it's rubber top, is this replaceable.

I think you can get lock covers in different colours, however you will need to gently pries of the cover to reveal the manual lock underneath. then look on the inside of the plastic cap and take a note of the code number there. google will then help to narrow down the part.:unsure: