No.6 Bofors Gun Tractor - Part ID

[Bob Moseley (RIP)]

Hi All
Helping with research on this configuration of Chev Blitz. There was a voice tube connecting the driver's compartment to the rear crew cab area and the attached image is possibly part of that system. Allegedly the voice tube started in the cab with a funnel type arrangement, a bit like a horn on a kid's bicycle, then exited the cab to the goose neck. There was a corresponding goose neck on the crew cab finishing up inside with another funnel. The two goose necks were coupled together with a rubber tube. Is this correct. My conception of a voice tube was one that exited behind the driver in a horizontal line and not vertical as the first theory suggests. Allegedly a similar system was also used on some ambulances.