I get a lot of questions about gearboxes. I hope this helps to answer some. I will add more as and when I get time...
180 rolling nut gearbox and number of teeth on each cog
125 rolling nut gearbox and number of teeth on each cog
Rolling nut case in the order in which it goes
Rolling nut and non-rolling nut
Rotations of the wheel in relation to the rotations of the clutch bell, or how to tell what gears you have.
Mark the clutch bell, turn the wheel once, and count how many times the clutch bell goes around.