285 L&G tractor, replacing throttle cable, new knob too?

[Zebrafive]

I have to replace the throttle cable on my JD 285 L& G tractor. The outer cable housing broke. Do I need to order the knob too? Can the old knob be transferred, or will it not survive being removed from the old throttle lever? You have to buy the lever as part of the cable. Key #1

 

[Zebrafive]

Update. The knob broke when trying to remove it from the old throttle lever. New one ordered.