I need help identifying this...
 

Hi All..
I recently bought some early auto parts from a guy and this was in the box
It looks like it would mount to a 1" vertical tube, It has a spring release on the latch that holds the arm up,the arm drops to 90 degrees,and there is a thumb tab to raise the arm back up.
All I can guess is its a vintage school bus stop signal??
ANYONE have any ideas???? Todd

It looks like a cross between a pendulum and a ball cock! No idea!.

A very warm welcome from the usually sunny Isle of Anglesey by the way, 44Tod.

Seems likely, but, as we don't have such things in the UK (we have school buses, but not the stop rule) I can't confirm your suggestion.

My guess is that it's some sort of "Do not Pass/Overtake" Weather it's for use when the vehicle is on the move or not is anybody's guess. Operated by the driver I imagine. Perhaps depending on the load.

This might give some clue that's worth following up.......

http://web.mit.edu/invent/iow/lawrencef.html