Thanks for your insight into this topic guys.
And Jon (winnie) thanks for the links.
Older electrical stuff really intrigues me.
I actually had one of the vibrator units in my possesion a few years back and I wanted to rip it open to see what was inside it, but I gave it to the radio museum instead.
I'm told that they came in 3 and 5(?) pin versions.
And don't forget that prior to the mid-1950s or thereabouts, most car electrical systems were 6 volts.
Hmm, now that I didn't know, to slide slightly off-topic here, the currents in a 12V system with headlamps and the horn are quite large as they are, a 6V system must have had huge
current draw, or were the lamps of a lower rating?.
Let's face it, these days if you're not young, you're old - Red Green