If you were in a cold climate, pulling the hand throttle warmed the engine up while you went back in the house and warmed up.
Isn't that the function of the choke and fast idle?
Obviously you have never driven a car with a manual choke and a manual throttle in a cold climate. You choked the car to get it started and then started opening the choke and pulling the throttle to keep the engine rpm up. Trying to keep the engine speed up with only the choke results in overchoking the engine as it warms up.
Guess I didn't grow up on the southern shore of Lake Michigan where the wind whistled down from Canada with nothing to stop it then tended to dump snow right on us. Until it warmed up you pretty much needed full choke to keep it running.
The old style choke worked differently then the newer ones. All they did was open or close the choke flap.They didn't have a fast idle linkage.
I daily drive a 51 Plymouth. In fact here is a link to it's automatic choke and fast idle setup
http://www.yourolddad.com/choke.
