Im not familiar with how the webers hook up to a b18. But I did quickly fab a cable linkage for the cruise control on my su/b18. Was easy enough, basic difference rod pushes cable pulls? (I'm 2nd guessing myself cant remember if the last throw of the linkage is push or pull, too lazy to go out and check)
Basically I made a little bracket that held the cable housing and attached the cable to the throttle arm.....so easy I have forgotten, I probably used bicycle parts.