Pictures would help. Sometimes if the sheet metal is there you need to build one, a good cabinet maker or best of all a buggy maker can get good connections and contours.
Metropolitan Body Co. of Bridgeport, Connecticut also had a factory in Ohio that built White truck cabs into the mid 1930s. That cab was also used on Sterlings and Pierce Arrow. P-A and Stewart were both in western New York state. Metro cabs had a brass plaque on the header holding the windshield and often had a map pocket on the back wall behind the passenger head.
Highland cabs were also common in that era, from Ohio. I don't know about Brockway cabs, also built in western NY.
Is your truck left hand drive or right?
1932 White 643 restored in the working museum