I invented a "CLUTCH DISENGAGER" after getting stuck in gear with the column shift on my 1966 C-10. I cut a 2x4 to a size that would depress the clutch pedal when placed lenghwise between the seat and pedal. This will allow you to free up the jammed linkage without involving another person. I don't need to use it often, but it can be a life saver when linkage gets jammed.
So, if you have one of these three on the tree rigs, it is a good idea to make a "CLUTCH DISENGAGER". Just make sure that you mark it as one, so that the cops will not accuse you of carrying a weapon in your vehicle.
Maybe I should patent this, and make a million bucks.
Doug 57