From Don Cox: "Acoustic recordings were often made with more than one horn.I haven't been able to find a picture of this, or to find out how the sounds were combined."
I've never heard of them being combined. The reason one would record that way would be to obtain multiple master disks from the same performance. This same redundancy was SOP for electrical and magnetic tape master recordings and is standard with today's digital gear.
Michael Shoshani Chicago