Using Campagnolo downtube shifters on thumb or bar-end mountsxq

[chriscross1966]

I've seen various videos tha texplain that you can use Shimano (and better still nice cheap SunRace and Sturmey) thumb and bar-end shifters as downtube shifters by adding in the cable-end holding washer (the one with the square hole and asort of bent tab on it) and bolting it to a downtube boss.... what I want to know is would it be possible to use say a Sunrace bar-end mount minus its lever to mount a Campagnolo Syncro on?.... Moon on a stick territory would be if I could find something like a Gevenalle or Retroshift system built onto old Campy brake levers...