First thing I would do is pull that collar off the cranks and switch them around. Looks like it'll be good to go if everything else fits.

When you engage the wide primary drive gear with the driven gear n the clutch you'll see that it's far wide than it needs to be any way. In moments of madness I machine the width down, which obviously lightens the gear, but not all the way to centre, just leave meat on the bolting faces. Must give a whopping 0.01% improvement. Maybe.