I need a diagram or instructions on how to wire up an old Bosch distributor.
I'm just guessing, but I would expect the one small wire would go to the (-) terminal on the coil.
As Tim said, the one small wire goes to the coil, the spark plug wires go in the same order as it fires in. With the Bosch there is no designated No1. When it is set up, which ever terminal the rotor is pointed to is No1. So every time it is taken off the terminal can change if the motor has been turned over.
Might this be of help?
I don't know about the Bosch but some of the early distributors were capable of being connected to fire a single buzz coil and distribute the spark to all four cylinders. The Atwater Kent had this feature.
if you have the book "The Model T Fordowner" the best of Murray Fahnestock it is on page 290. Lange's has the book. They also have The article for Bosch deluxe, front plate for sale.