Best I can tell from the picture, they are 1958 or 1959 Arrowmate 4 blade manufactured in Milwaukee, WI.
The differences between the two: the 1958 main blade is outside of Ferrule, and the 1959 main blade is molded into the ferrule. You have to look at the shaft end of the ferrule.
The plastic ferrules are available in black, blue, red, green, white and yellow.
A very common head, but great in a collection with the different colors.