No pix unfortunately but mine has a similar system with a link from the center carb with a loop over the rod that connects to the 2 end carbs , mine has a slider with a set screw that can be adjusted so the link from the center carb allow the center carb to open 30 % or so before the end carbs start to open but still allows full opening of all the carbs at one time , So it would seem we both have the same system , the upper rod has a pivot / nut / part that fits the large upper loop on the arm & uses a cotter pin & washer to retain it I recall .
Not sure where to find that part but Brad could make one in a few minutes !!