On those 12BB PowerHo's, the clutch handle to engage the drive was in the other bracket, closest to the handle. .....The handle to engage a belt-driven attachment would mount in the bracket where you have your handle.
The 12BB also had a stop-switch button mounted in front of the left handlegrip. ....The button mounted on an insulating bushing, and when pressed down, would short the ignition to the handlebar, shutting off the engine.
I altered the handles from offset to centered directly behind the frame. The throttle and stop button were
altered into a small "dash panel". I have the original items. These changes may not be "kosher" but I wanted them. I will use a snow plow on this unit hence the desire for centered handles. That put the clutch handle in the other location. I understand the need to keep the unit
'correct' but the challenge to change the handles while maintaining the geometry was too much
for me to resist.