You might try searching for vehicles under the Ford/Marmon-Herrington names.
I believe it was built on one of the COE type chassis.
Came up with these, not exactly what you are looking for but these are prewar 6x4 and 6x6 Ford fire trucks.
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The first Sandwich brush breaker was this 1938 Ford cab over built by
Buffalo Fire Apparatus. It had an 85 hp V8 motor and carried 1000 gallons of water.
The Sandwich breaker had only rear wheel drive and was somewhat under powered
according to sources. It served Sandwich until 1965.
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County No.1 had an 85 hp flathead Ford motor, 125 gpm pump, and carried 1000 gallons
of water with a road speed of 30-40 mph.
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The first brush breaker was built in 1939 on a Ford cab over chassis.
It had a Marmon Harrington all wheel drive transmission and was built by
Robinson Boiler Company in Cambridge, Massachusetts.
Good luck in finding the version you are looking for.