Aircooled VW South Africa

A quick one for the engine boffins:

How can I tell at a glance the difference between "6V" and "12V" 200mm flywheels?

I'm busy swapping transmissions in one of my buses and I noticed the flywheel teeth are all chewed up. I'm taking the engine to McDonalds in the morning to fit a new FW and set up the crank end float, and I want to be sure to take the correct flywheel. The bus is a 75 Fleetline. And what should I look for on the starter motor to cause damage to the flywheel teeth?

Think the 6 volt flywheel has 109 teeth and the 12 volt one 130 teeth.
Hope this helps.

I believe that the 6v FW is smaller in dia.(obvious actually, seeing that the 6v has got 109 teeth vs. 132 teeth on a 12v) Recall having to 'massage' a 6v g/box bellhousing to put in a 12v(read: later type) engine in a Bug, while working at my old job....