I see with my pclinuxos, in configure your desktop/hardware/input devices/keyboard, then the hardware tab, that I can choose the keyboard model here that I am using. My particular brand is not showing Logitech Cordless Desktop MX 5500 Revolution (it is bluetooth).

Is there a list somewhere that says which of the keyboard choices to use for a particular model number? If not, does someone know which one to use for my model?

Thanks!

Unfortunately I am not aware of any - the list of layouts you see is not provided by KDE but by X itself. In this case, I can only advise trying devices with a similar model number, or Googling the model you have alongside "linux keyboard layout" or similar terms.