4 bolts it will be in that case. The parts diagram (see Draganfly website) shows 2 studs, 2 bolts. I was annoyed at having to remove the mag to get the studs out as I had just replaced it and timed it up. Ho hum. Sitting nearby is the Velocette looking smug. To remove gearbox sprocket: Remove pressed steel cover (2 nuts), remove gearbox sprocket (1 nut).
Not going for the full engine rebuild. It was going beautifully before this (as it has been doing for years and years) and I want it back on the road. It's my most useful, reliable, all purpose bike.