Conn 6E New Wonder Eb French horn Alto
Date: 1924. (Drawing)
It is interesting to note that in spite of the fact that this instrument looks like a mellophone and the model number indicates it is a mellophone (6-"E"), it is called an "Alto". The 6E is the Low Pitch version, the High Pitch is the 7E. The 6E around 1924. It had a #3 (0.500") bore size.
What Conn said in 1924:
The "French Horn" model produces a tone of quality similar to the instrument after which it is named, and it is frequently used in place of this instrument in orchestras and bands where performers are unable to devote the time necessary to cultivate and retain the embouchure for the latter instrument.