Rob,
Yes, the C32 would use the same cone clutch drive built into the face of the magneto gear wheel. On the dyno would be a small pinion. If the same as the other lightweights (and no reason to assume not), this would be 14 teeth.
The drive was probably disconnected because even when all was operating properly, the BTH pancake dynamo put out all of about 22 watts. Perhaps a telling bit in the advertising of the lighting set was the following:
"The system is simplicity itself with the added advantage that the generator can always be removed and the fixing hole blanked off, which means the machine need not be out of commission should a slight defect become manifest in the generator."
Almost seems they anticipated troubles! Anyway, the output is pretty meager and rapidly approaches nil if there is any problem with the armature or the magnets have lost their strength (or cracked, introducing extra north-south poles).
-Doug
