In August 1931 Ford adopted the all-steel truck cab 82-B manufactured by the Budd Company for both Model A and AA trucks. The internal roof bows were also steel.
The earlier 82-B pickup cabs were constructed similar to Model A coupes and tudors, having a wooden roof structure covered by a long-short grain fabric-backed top material.
Pictured above is a 1931 Model AA dump truck with a Budd steel top cab.
The pic above shows the front construction of the cab. The windshield visor is part of the roof panel stamping, and the rain gutters are spot welded to the roof panel.
In the previous 82-B design cab, the roof had a separate visor, and a trim moulding covering the joint, the same as the 1930-31 Tudor sedan. The earlier truck rain gutters were also separate parts with the same construction and attachment as found on Tudor sedans.
Also note the screws along the front edge of the roof panel and the stamped-in "countersunk washers" in the roof panel stamping in the Budd cab.
Pictured above is a close-up of the roof panel and back panel joint and construction.