Diamond T was a large sized truck manufacturing company and it became too expensive to compete with Ford, Chevy, and International in the small truck market thus the end of small trucks.
Contact Steve Rutledge at firstname.lastname@example.org
,, He has a lot of the production information, sales literature, some specs, and possibly some pictures of that sized DT's of the era.
As far as value, it all boils down to being in the right place at the right time!! Finding a buyer who understands the scarcity and wants that particular vehicle.
Diamond T and Brockway Collector