[Jack Innes]

This looks like a distributor with the coil & likely the condenser built in to the box affair which is part of the casting. The cap is similir in design to the early Delco caps used on pre-teens Cadillac 4 cylinder cars. The rotor has a carbon brush that connects the center electrode to the respective plug wires as it turns. The rheostat looking thing is likely a spark intensifier of sorts. The dwell would not be altered by the wide cap contacts, the width assures contact throughout the spark advance movement - avoiding any degree of arking is important with this set up. The dwell is controlled by the point setting.


Below is a DELCO cap for a 1911 Cadillac; ( I need one & a rotor if anyone has anything like this)