For all you folks who are certain that Model A's did not come from the factory with turn signals, think again. Sorry to say this, but Model A's, at least here in Germany, did originally come from the factory with turn signals!
What you all are calling "semaphores" are properly termed trafficators......turn signals where, when switched on, the little orange lighted arm swings up indicating the intended turn direction.
If there is any doubt about original trafficators on Model A's, here is a factory photo from the Köln Ford production line with the original trafficators already installed on the body (circled in red).
Since they were a requirement here in Germany (and several other European countries as well) there were many different manufactureres of these trafficators. Some even came with Ford scripts on the turn signal arm.
Here is a photo of several variations of them:
....and an NOS set:
Hope that clarifies the original turn signal thing....at least for German Model A's
Fordially,
Brad in Germany