Is it for a car? or an old toilet flushing lever? Both?

No identifying marks that I can see. Has a nice spring loaded detent. Seems to be very well made. I'm used to dealing with VW cars / parts which are always marked with VW logo and 95% of the time with a part #. Not that way with alot of American stuff. We should have enough pride to put our mark on it. Or maybe our forefathers did that to create an element of mystery in the future.

From the 1913 Stromberg carburetor catalog

I am floored!! This is the best site I have ever found on the internet!! It's like a replacement dad. I used to just ask him: What's this? What's it for? Why? How come? He almost always had an answer and if he didn't it would catch his interest and we'd both investigate until the answer was known. I am officially declaring this site as my adopted dad!!!

Or as Bruce McCalley of the Model T Ford Club says "first liar has the best chance".

Now THAT is an amazing ID, even for a sharp site like this one.

I can't imagine the bidding wars on that part, as whistles, horns and exhaust cut-outs all demand good prices for the early car crowd. Nice find.

Their reference to "air horn" is the air intake to the carburetor hence this is a choke control lever.

Nice ID, I like the artwork in the add with the faded carb and dash.