In my fumbling enthusiasm to get out from under the kitchen sink, I overdid the leverage and broke the spindle of a seized gate valve. So now it can be turned forever in any direction with no effect.
Will I have to replace the whole thing, or can I remove the guts from the main body of the valve and renew just those inner parts?
In my next life I intend to move into my retirement accommodation long before I become "stiff where once I was supple, and supple where once I was stiff".