Did any and if so which, model Penton, ever use a trapdoor made for (2) cables?
All the early steel tank Penton bikes from 1968 thru 1971 came with the Magura trap door throttle for 2 cables. It was the best throttle available at the time (used on the BMW bikes) until Magura revised it and came out with the single cable trap door throttle.
thanks Al.