timer assy question?

[kwisor]

hello
I have a 1923 t i have had a true fire system for over 30 years but i think it is going bad i am going to switch back to the coils and timer and roller assy my questions is witch way dose the roller go on the shaft which part of update I found that the wire harness from coil box to timer was bad replaced and now back to driving again thanks for all the suggestions it helped very much Kevin