bonus picture: this is not in the contest but I thought you might have liked it anyway. It's a period ad of the Bosch BTZ ignition, showing its basic circuit. The BTZ was offered in kits for the most popular Italian and Japanese twin and fours of the time that employed points as standard. The system described is for a four cylinder bike and employs double-lead HT coils.
well by now you must have pondered over the photos and probably you have even found an answer. So:
